diff --git a/src/bin/gs_guc/cluster_guc.conf b/src/bin/gs_guc/cluster_guc.conf
index b9ad7f149..43564816f 100644
--- a/src/bin/gs_guc/cluster_guc.conf
+++ b/src/bin/gs_guc/cluster_guc.conf
@@ -154,6 +154,7 @@ enable_copy_server_files|bool|0,0|NULL|NULL|
 enable_sonic_hashjoin|bool|0,0|NULL|NULL|
 enable_sonic_hashagg|bool|0,0|NULL|NULL|
 enable_sonic_optspill|bool|0,0|NULL|NULL|
+enable_upsert_to_merge|bool|0,0|NULL|Enable transform INSERT ON DUPLICATE KEY UDPATE statement to MERGE statement.|
 enable_codegen|bool|0,0|NULL|NULL|
 enable_codegen_print|bool|0,0|NULL|Enable dump for llvm function|
 enable_delta_store|bool|0,0|NULL|NULL|
diff --git a/src/common/backend/catalog/index.cpp b/src/common/backend/catalog/index.cpp
index d642a72b1..6be9454f3 100755
--- a/src/common/backend/catalog/index.cpp
+++ b/src/common/backend/catalog/index.cpp
@@ -1814,7 +1814,13 @@ IndexInfo* BuildIndexInfo(Relation index)
     /* fetch exclusion constraint info if any */
     if (indexStruct->indisexclusion) {
         RelationGetExclusionInfo(index, &ii->ii_ExclusionOps, &ii->ii_ExclusionProcs, &ii->ii_ExclusionStrats);
-    } 
+    }
+
+    /* not doing speculative insertion here */
+    ii->ii_UniqueOps = NULL;
+    ii->ii_UniqueProcs = NULL;
+    ii->ii_UniqueStrats = NULL;
+
     return ii;
 }
 
@@ -1865,6 +1871,42 @@ IndexInfo* BuildDummyIndexInfo(Relation index)
     return ii;
 }
 
+void BuildSpeculativeIndexInfo(Relation index, IndexInfo* ii)
+{
+    int ncols = index->rd_rel->relnatts;
+    int i;
+
+    /*
+     * fetch info for checking unique indexes
+     */
+    Assert(ii->ii_Unique);
+
+    if (index->rd_rel->relam != BTREE_AM_OID) {
+        ereport(ERROR,
+            (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+            errmsg("unexpected non-btree speculative unique index")));
+    }
+
+    ii->ii_UniqueOps = (Oid*) palloc(sizeof(Oid) * ncols);
+    ii->ii_UniqueProcs = (Oid*) palloc(sizeof(Oid) * ncols);
+    ii->ii_UniqueStrats = (uint16*) palloc(sizeof(uint16) * ncols);
+
+    /*
+     * We have to look up the operator's strategy number.  This
+     * provides a cross-check that the operator does match the index.
+     *
+     * We need the func OIDs and strategy numbers too
+     */
+    for (i = 0; i < ncols; i++) {
+        ii->ii_UniqueStrats[i] = BTEqualStrategyNumber;
+        ii->ii_UniqueOps[i] = get_opfamily_member(index->rd_opfamily[i],
+            index->rd_opcintype[i],
+            index->rd_opcintype[i],
+            ii->ii_UniqueStrats[i]);
+        ii->ii_UniqueProcs[i] = get_opcode(ii->ii_UniqueOps[i]);
+    }
+}
+
 /* ----------------
  *		FormIndexDatum
  *			Construct values[] and isnull[] arrays for a new index tuple.
diff --git a/src/common/backend/catalog/indexing.cpp b/src/common/backend/catalog/indexing.cpp
index ea710c878..16f911de0 100644
--- a/src/common/backend/catalog/indexing.cpp
+++ b/src/common/backend/catalog/indexing.cpp
@@ -45,7 +45,7 @@ CatalogIndexState CatalogOpenIndexes(Relation heapRel)
     resultRelInfo->ri_RelationDesc = heapRel;
     resultRelInfo->ri_TrigDesc = NULL; /* we don't fire triggers */
 
-    ExecOpenIndices(resultRelInfo);
+    ExecOpenIndices(resultRelInfo, false);
 
     return resultRelInfo;
 }
diff --git a/src/common/backend/catalog/storage_gtt.cpp b/src/common/backend/catalog/storage_gtt.cpp
index 9fab21762..4300e82e4 100644
--- a/src/common/backend/catalog/storage_gtt.cpp
+++ b/src/common/backend/catalog/storage_gtt.cpp
@@ -1427,7 +1427,7 @@ void gtt_create_storage_files(Oid relid)
     InitResultRelInfo(resultRelInfo, rel, 1, 0);
     if (resultRelInfo->ri_RelationDesc->rd_rel->relhasindex &&
         resultRelInfo->ri_IndexRelationDescs == NULL) {
-        ExecOpenIndices(resultRelInfo);
+        ExecOpenIndices(resultRelInfo, false);
     }
     init_gtt_storage(CMD_UTILITY, resultRelInfo);
     relation_close(rel, NoLock);
diff --git a/src/common/backend/nodes/copyfuncs.cpp b/src/common/backend/nodes/copyfuncs.cpp
index 22ab1ce20..8dc1db1f2 100644
--- a/src/common/backend/nodes/copyfuncs.cpp
+++ b/src/common/backend/nodes/copyfuncs.cpp
@@ -283,6 +283,11 @@ static ModifyTable* _copyModifyTable(const ModifyTable* from)
     COPY_NODE_FIELD(mergeSourceTargetList);
     COPY_NODE_FIELD(mergeActionList);
 
+    COPY_SCALAR_FIELD(upsertAction);
+    COPY_NODE_FIELD(updateTlist);
+    COPY_NODE_FIELD(exclRelTlist);
+    COPY_SCALAR_FIELD(exclRelRTIndex);
+
     return newnode;
 }
 
@@ -3264,6 +3269,7 @@ static RangeTblEntry* _copyRangeTblEntry(const RangeTblEntry* from)
     COPY_SCALAR_FIELD(relhasbucket);
     COPY_SCALAR_FIELD(isbucket);
     COPY_NODE_FIELD(buckets);
+    COPY_SCALAR_FIELD(isexcluded);
 
     return newnode;
 }
@@ -3341,6 +3347,28 @@ static WithClause* _copyWithClause(const WithClause* from)
     return newnode;
 }
 
+static UpsertClause* _copyUpsertClause(const UpsertClause* from)
+{
+    UpsertClause* newnode = makeNode(UpsertClause);
+
+    COPY_NODE_FIELD(targetList);
+    COPY_LOCATION_FIELD(location);
+
+    return newnode;
+}
+
+static UpsertExpr* _copyUpsertExpr(const UpsertExpr* from)
+{
+    UpsertExpr* newnode = makeNode(UpsertExpr);
+
+    COPY_SCALAR_FIELD(upsertAction);
+    COPY_NODE_FIELD(updateTlist);
+    COPY_NODE_FIELD(exclRelTlist);
+    COPY_SCALAR_FIELD(exclRelIndex);
+
+    return newnode;
+}
+
 static CommonTableExpr* _copyCommonTableExpr(const CommonTableExpr* from)
 {
     CommonTableExpr* newnode = makeNode(CommonTableExpr);
@@ -3981,6 +4009,7 @@ static Query* _copyQuery(const Query* from)
     COPY_NODE_FIELD(mergeSourceTargetList);
     COPY_NODE_FIELD(mergeActionList);
     COPY_NODE_FIELD(upsertQuery);
+    COPY_NODE_FIELD(upsertClause);
     COPY_SCALAR_FIELD(isRowTriggerShippable);
     COPY_SCALAR_FIELD(use_star_targets);
     COPY_SCALAR_FIELD(is_from_full_join_rewrite);
@@ -3998,6 +4027,7 @@ static InsertStmt* _copyInsertStmt(const InsertStmt* from)
     COPY_NODE_FIELD(selectStmt);
     COPY_NODE_FIELD(returningList);
     COPY_NODE_FIELD(withClause);
+    COPY_NODE_FIELD(upsertClause);
     return newnode;
 }
 
@@ -6164,6 +6194,9 @@ void* copyObject(const void* from)
         case T_FromExpr:
             retval = _copyFromExpr((FromExpr*)from);
             break;
+        case T_UpsertExpr:
+            retval = _copyUpsertExpr((UpsertExpr *)from);
+            break;
         case T_PartitionState:
             retval = _copyPartitionState((PartitionState*)from);
             break;
@@ -6701,6 +6734,9 @@ void* copyObject(const void* from)
         case T_WithClause:
             retval = _copyWithClause((WithClause*)from);
             break;
+        case T_UpsertClause:
+            retval = _copyUpsertClause((UpsertClause *)from);
+            break;
         case T_CommonTableExpr:
             retval = _copyCommonTableExpr((CommonTableExpr*)from);
             break;
diff --git a/src/common/backend/nodes/equalfuncs.cpp b/src/common/backend/nodes/equalfuncs.cpp
index 41c52a839..2e9cbe382 100755
--- a/src/common/backend/nodes/equalfuncs.cpp
+++ b/src/common/backend/nodes/equalfuncs.cpp
@@ -680,6 +680,15 @@ static bool _equalMergeAction(const MergeAction* a, const MergeAction* b)
     return true;
 }
 
+static bool _equalUpsertExpr(const UpsertExpr* a, const UpsertExpr* b)
+{
+    COMPARE_SCALAR_FIELD(upsertAction);
+    COMPARE_NODE_FIELD(updateTlist);
+    COMPARE_NODE_FIELD(exclRelTlist);
+    COMPARE_SCALAR_FIELD(exclRelIndex);
+
+    return true;
+}
 /*
  * Stuff from relation.h
  */
@@ -818,6 +827,7 @@ static bool _equalQuery(const Query* a, const Query* b)
     COMPARE_NODE_FIELD(mergeSourceTargetList);
     COMPARE_NODE_FIELD(mergeActionList);
     COMPARE_NODE_FIELD(upsertQuery);
+    COMPARE_NODE_FIELD(upsertClause);
     COMPARE_SCALAR_FIELD(isRowTriggerShippable);
     COMPARE_SCALAR_FIELD(use_star_targets);
     COMPARE_SCALAR_FIELD(is_from_full_join_rewrite);
@@ -832,6 +842,7 @@ static bool _equalInsertStmt(const InsertStmt* a, const InsertStmt* b)
     COMPARE_NODE_FIELD(selectStmt);
     COMPARE_NODE_FIELD(returningList);
     COMPARE_NODE_FIELD(withClause);
+    COMPARE_NODE_FIELD(upsertClause);
 
     return true;
 }
@@ -2310,6 +2321,7 @@ static bool _equalRangeTblEntry(const RangeTblEntry* a, const RangeTblEntry* b)
     COMPARE_SCALAR_FIELD(relhasbucket);
     COMPARE_SCALAR_FIELD(isbucket);
     COMPARE_NODE_FIELD(buckets);
+    COMPARE_SCALAR_FIELD(isexcluded);
 
     return true;
 }
@@ -2387,6 +2399,13 @@ static bool _equalWithClause(const WithClause* a, const WithClause* b)
     return true;
 }
 
+static bool _equalUpsertClause(const UpsertClause* a, const UpsertClause* b)
+{
+    COMPARE_NODE_FIELD(targetList);
+    COMPARE_LOCATION_FIELD(location);
+
+   return true;
+}
 static bool _equalCommonTableExpr(const CommonTableExpr* a, const CommonTableExpr* b)
 {
     COMPARE_STRING_FIELD(ctename);
@@ -2892,6 +2911,9 @@ bool equal(const void* a, const void* b)
         case T_FromExpr:
             retval = _equalFromExpr((FromExpr*)a, (FromExpr*)b);
             break;
+        case T_UpsertExpr:
+            retval = _equalUpsertExpr((UpsertExpr*)a, (UpsertExpr*)b);
+            break;
         case T_JoinExpr:
             retval = _equalJoinExpr((JoinExpr*)a, (JoinExpr*)b);
             break;
@@ -3429,6 +3451,9 @@ bool equal(const void* a, const void* b)
         case T_WithClause:
             retval = _equalWithClause((WithClause*)a, (WithClause*)b);
             break;
+        case T_UpsertClause:
+            retval = _equalUpsertClause((UpsertClause*)a, (UpsertClause*)b);
+            break;
         case T_CommonTableExpr:
             retval = _equalCommonTableExpr((CommonTableExpr*)a, (CommonTableExpr*)b);
             break;
diff --git a/src/common/backend/nodes/nodeFuncs.cpp b/src/common/backend/nodes/nodeFuncs.cpp
index 513774d1a..698fa8ca1 100755
--- a/src/common/backend/nodes/nodeFuncs.cpp
+++ b/src/common/backend/nodes/nodeFuncs.cpp
@@ -1372,6 +1372,9 @@ int exprLocation(const Node* expr)
         case T_WithClause:
             loc = ((const WithClause*)expr)->location;
             break;
+        case T_UpsertClause:
+            loc = ((const UpsertClause*)expr)->location;
+            break;
         case T_CommonTableExpr:
             loc = ((const CommonTableExpr*)expr)->location;
             break;
@@ -1781,6 +1784,11 @@ bool expression_tree_walker(Node* node, bool (*walker)(), void* context)
                 return true;
             }
         } break;
+        case T_UpsertExpr: {
+            UpsertExpr* upsertClause = (UpsertExpr*)node;
+            if (p2walker(upsertClause->updateTlist, context))
+                return true;
+        } break;
         case T_JoinExpr: {
             JoinExpr* join = (JoinExpr*)node;
 
@@ -1880,6 +1888,9 @@ bool query_tree_walker(Query* query, bool (*walker)(), void* context, int flags)
     if (p2walker((Node*)query->mergeActionList, context)) {
         return true;
     }
+    if (p2walker((Node*)query->upsertClause, context)) {
+        return true;
+    }
     if (p2walker((Node*)query->returningList, context)) {
         return true;
     }
@@ -2468,6 +2479,14 @@ Node* expression_tree_mutator(Node* node, Node* (*mutator)(Node*, void*), void*
             }
             return (Node*)resultlist;
         } break;
+        case T_UpsertExpr: {
+            UpsertExpr* upsertClause = (UpsertExpr*)node;
+            UpsertExpr* newnode = NULL;
+
+            FLATCOPY(newnode, upsertClause, UpsertExpr, isCopy);
+            MUTATE(newnode->updateTlist, upsertClause->updateTlist, List*);
+            return (Node*)newnode;
+        } break;
         case T_FromExpr: {
             FromExpr* from = (FromExpr*)node;
             FromExpr* newnode = NULL;
@@ -2586,6 +2605,7 @@ Query* query_tree_mutator(Query* query, Node* (*mutator)(Node*, void*), void* co
     MUTATE(query->targetList, query->targetList, List*);
     MUTATE(query->mergeSourceTargetList, query->mergeSourceTargetList, List*);
     MUTATE(query->mergeActionList, query->mergeActionList, List*);
+    MUTATE(query->upsertClause, query->upsertClause, UpsertExpr*);
     MUTATE(query->returningList, query->returningList, List*);
     MUTATE(query->jointree, query->jointree, FromExpr*);
     MUTATE(query->setOperations, query->setOperations, Node*);
@@ -2853,6 +2873,9 @@ bool raw_expression_tree_walker(Node* node, bool (*walker)(), void* context)
             if (p2walker(stmt->withClause, context)) {
                 return true;
             }
+            if (p2walker(stmt->upsertClause, context)) {
+                return true;
+            }
         } break;
         case T_DeleteStmt: {
             DeleteStmt* stmt = (DeleteStmt*)node;
@@ -3144,6 +3167,8 @@ bool raw_expression_tree_walker(Node* node, bool (*walker)(), void* context)
         } break;
         case T_WithClause:
             return p2walker(((WithClause*)node)->ctes, context);
+        case T_UpsertClause:
+            return p2walker(((UpsertClause*)node)->targetList, context);
         case T_CommonTableExpr:
             return p2walker(((CommonTableExpr*)node)->ctequery, context);
         default:
diff --git a/src/common/backend/nodes/outfuncs.cpp b/src/common/backend/nodes/outfuncs.cpp
index af0ea3ccb..41c48689d 100755
--- a/src/common/backend/nodes/outfuncs.cpp
+++ b/src/common/backend/nodes/outfuncs.cpp
@@ -735,8 +735,30 @@ static void _outModifyTable(StringInfo str, ModifyTable* node)
     WRITE_INT_FIELD(mergeTargetRelation);
     WRITE_NODE_FIELD(mergeSourceTargetList);
     WRITE_NODE_FIELD(mergeActionList);
+
+    WRITE_ENUM_FIELD(upsertAction, UpsertAction);
+    WRITE_NODE_FIELD(updateTlist);
+    WRITE_NODE_FIELD(exclRelTlist);
+    WRITE_INT_FIELD(exclRelRTIndex);
 }
 
+static void _outUpsertClause(StringInfo str, const UpsertClause* node)
+{
+    WRITE_NODE_TYPE("UPSERTCLAUSE");
+
+    WRITE_NODE_FIELD(targetList);
+    WRITE_INT_FIELD(location);
+}
+
+static void _outUpsertExpr(StringInfo str, const UpsertExpr* node)
+{
+    WRITE_NODE_TYPE("UPSERTEXPR");
+
+    WRITE_ENUM_FIELD(upsertAction, UpsertAction);
+    WRITE_NODE_FIELD(updateTlist);
+    WRITE_NODE_FIELD(exclRelTlist);
+    WRITE_INT_FIELD(exclRelIndex);
+}
 static void _outMergeWhenClause(StringInfo str, const MergeWhenClause* node)
 {
     WRITE_NODE_TYPE("MERGEWHENCLAUSE");
@@ -3317,6 +3339,8 @@ static void _outInsertStmt(StringInfo str, InsertStmt* node)
     WRITE_NODE_FIELD(selectStmt);
     WRITE_NODE_FIELD(returningList);
     WRITE_NODE_FIELD(withClause);
+
+    WRITE_NODE_FIELD(upsertClause);
 }
 
 static void _outUpdateStmt(StringInfo str, UpdateStmt* node)
@@ -3771,6 +3795,7 @@ static void _outQuery(StringInfo str, Query* node)
     WRITE_NODE_FIELD(mergeSourceTargetList);
     WRITE_NODE_FIELD(mergeActionList);
     WRITE_NODE_FIELD(upsertQuery);
+    WRITE_NODE_FIELD(upsertClause);
     WRITE_BOOL_FIELD(isRowTriggerShippable);
     WRITE_BOOL_FIELD(use_star_targets);
     WRITE_BOOL_FIELD(is_from_full_join_rewrite);
@@ -3986,6 +4011,7 @@ static void _outRangeTblEntry(StringInfo str, RangeTblEntry* node)
         WRITE_BOOL_FIELD(isbucket);
         WRITE_NODE_FIELD(buckets);
     }
+    WRITE_BOOL_FIELD(isexcluded);
 }
 
 /*
@@ -5116,7 +5142,9 @@ static void _outNode(StringInfo str, const void* obj)
             case T_MergeAction:
                 _outMergeAction(str, (MergeAction*)obj);
                 break;
-
+            case T_UpsertExpr:
+                _outUpsertExpr(str, (UpsertExpr*)obj);
+                break;
             case T_Path:
                 _outPath(str, (Path*)obj);
                 break;
@@ -5289,6 +5317,9 @@ static void _outNode(StringInfo str, const void* obj)
             case T_WithClause:
                 _outWithClause(str, (WithClause*)obj);
                 break;
+            case T_UpsertClause:
+                _outUpsertClause(str, (UpsertClause*)obj);
+                break;
             case T_CommonTableExpr:
                 _outCommonTableExpr(str, (CommonTableExpr*)obj);
                 break;
diff --git a/src/common/backend/nodes/readfuncs.cpp b/src/common/backend/nodes/readfuncs.cpp
index 7b913aa54..26493109e 100644
--- a/src/common/backend/nodes/readfuncs.cpp
+++ b/src/common/backend/nodes/readfuncs.cpp
@@ -1304,6 +1304,9 @@ static Query* _readQuery(void)
     IF_EXIST(upsertQuery) {
         READ_NODE_FIELD(upsertQuery);
     }
+    IF_EXIST(upsertClause) {
+        READ_NODE_FIELD(upsertClause);
+    }
     IF_EXIST(isRowTriggerShippable) {
         READ_BOOL_FIELD(isRowTriggerShippable);
     }
@@ -2659,6 +2662,10 @@ static RangeTblEntry* _readRangeTblEntry(void)
         READ_NODE_FIELD(buckets);
     }
 
+    IF_EXIST(isexcluded) {
+        READ_BOOL_FIELD(isexcluded);
+    }
+
     READ_DONE();
 }
 
@@ -3392,6 +3399,44 @@ static ModifyTable* _readModifyTable(ModifyTable* local_node)
         READ_NODE_FIELD(mergeActionList);
     }
 
+    IF_EXIST(upsertAction) {
+        READ_ENUM_FIELD(upsertAction, UpsertAction);
+    }
+
+    IF_EXIST(updateTlist) {
+        READ_NODE_FIELD(updateTlist);
+    }
+
+    IF_EXIST(exclRelTlist) {
+        READ_NODE_FIELD(exclRelTlist);
+    }
+
+    IF_EXIST(exclRelRTIndex) {
+        READ_INT_FIELD(exclRelRTIndex);
+    }
+
+    READ_DONE();
+}
+
+static UpsertExpr* _readUpsertExpr(void)
+{
+    READ_LOCALS(UpsertExpr);
+
+    READ_ENUM_FIELD(upsertAction, UpsertAction);
+    READ_NODE_FIELD(updateTlist);
+    READ_NODE_FIELD(exclRelTlist);
+    READ_INT_FIELD(exclRelIndex);
+
+    READ_DONE();
+}
+
+static UpsertClause* _readUpsertClause(void)
+{
+    READ_LOCALS(UpsertClause);
+
+    READ_NODE_FIELD(targetList);
+    READ_INT_FIELD(location);
+
     READ_DONE();
 }
 
@@ -5197,6 +5242,10 @@ Node* parseNodeString(void)
         return_value = _readAddPartitionState();
     } else if (MATCH("ROWNUM", 6)) {
         return_value = _readRownum();
+    } else if (MATCH("UPSERTEXPR", 10)) {
+        return_value = _readUpsertExpr();
+    } else if (MATCH("UPSERTCLAUSE", 12)) {
+        return_value = _readUpsertClause();
     } else {
         ereport(ERROR,
             (errcode(ERRCODE_UNRECOGNIZED_NODE_TYPE),
diff --git a/src/common/backend/parser/analyze.cpp b/src/common/backend/parser/analyze.cpp
index 338693cfe..f0c3b62e2 100644
--- a/src/common/backend/parser/analyze.cpp
+++ b/src/common/backend/parser/analyze.cpp
@@ -82,6 +82,8 @@ THR_LOCAL post_parse_analyze_hook_type post_parse_analyze_hook = NULL;
 
 static Query* transformDeleteStmt(ParseState* pstate, DeleteStmt* stmt);
 static Query* transformInsertStmt(ParseState* pstate, InsertStmt* stmt);
+static void checkUpsertTargetlist(Relation targetTable, List* updateTlist);
+static UpsertExpr* transformUpsertClause(ParseState* pstate, UpsertClause* upsertClause, RangeVar* relation);
 static int count_rowexpr_columns(ParseState* pstate, Node* expr);
 static Query* transformSelectStmt(
     ParseState* pstate, SelectStmt* stmt, bool isFirstNode = true, bool isCreateView = false);
@@ -90,6 +92,7 @@ static Query* transformSetOperationStmt(ParseState* pstate, SelectStmt* stmt);
 static Node* transformSetOperationTree(ParseState* pstate, SelectStmt* stmt, bool isTopLevel, List** targetlist);
 static void determineRecursiveColTypes(ParseState* pstate, Node* larg, List* nrtargetlist);
 static Query* transformUpdateStmt(ParseState* pstate, UpdateStmt* stmt);
+static List* transformUpdateTargetList(ParseState* pstate, List* qryTlist, List* origTlist, RangeVar* stmtrel);
 static List* transformReturningList(ParseState* pstate, List* returningList);
 static Query* transformDeclareCursorStmt(ParseState* pstate, DeclareCursorStmt* stmt);
 static Query* transformExplainStmt(ParseState* pstate, ExplainStmt* stmt);
@@ -1002,6 +1005,7 @@ static Query* transformInsertStmt(ParseState* pstate, InsertStmt* stmt)
     ListCell* icols = NULL;
     ListCell* attnos = NULL;
     ListCell* lc = NULL;
+    AclMode    targetPerms = ACL_INSERT;
 
     /* There can't be any outer WITH to worry about */
     AssertEreport(pstate->p_ctenamespace == NIL, MOD_OPT, "para should be NIL");
@@ -1068,7 +1072,10 @@ static Query* transformInsertStmt(ParseState* pstate, InsertStmt* stmt)
      * mentioned in the SELECT part.  Note that the target table is not added
      * to the joinlist or namespace.
      */
-    qry->resultRelation = setTargetTable(pstate, stmt->relation, false, false, ACL_INSERT);
+    if (stmt->upsertClause != NULL && stmt->upsertClause->targetList != NIL) {
+        targetPerms |= ACL_UPDATE;
+    }
+    qry->resultRelation = setTargetTable(pstate, stmt->relation, false, false, targetPerms);
     if (pstate->p_target_relation != NULL &&
         ((unsigned int)RelationGetInternalMask(pstate->p_target_relation) & INTERNAL_MASK_DINSERT)) {
         ereport(ERROR,
@@ -1076,6 +1083,23 @@ static Query* transformInsertStmt(ParseState* pstate, InsertStmt* stmt)
                 errmsg("Un-support feature"),
                 errdetail("internal relation doesn't allow INSERT")));
     }
+    if (pstate->p_target_relation != NULL && stmt->upsertClause != NULL) {
+        /* non-supported upsert cases */
+        if (!u_sess->attr.attr_sql.enable_upsert_to_merge && RelationIsColumnFormat(pstate->p_target_relation)) {
+            ereport(ERROR, ((errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+                             errmsg("INSERT ON DUPLICATE KEY UPDATE is not supported on column orientated table."))));
+        }
+
+        if (RelationIsForeignTable(pstate->p_target_relation)) {
+            ereport(ERROR, ((errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+                             errmsg("INSERT ON DUPLICATE KEY UPDATE is not supported on foreign table."))));
+        }
+
+        if (RelationIsView(pstate->p_target_relation)) {
+            ereport(ERROR, ((errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+                            errmsg("INSERT ON DUPLICATE KEY UPDATE is not supported on VIEW."))));
+        }
+    }
 
     /* data redistribution for DFS table.
      * check if the target relation is being redistributed(insert mode).
@@ -1439,6 +1463,11 @@ static Query* transformInsertStmt(ParseState* pstate, InsertStmt* stmt)
         attnos = lnext(attnos);
     }
 
+    /* Process DUPLICATE KEY UPDATE, if any. */
+    if (stmt->upsertClause) {
+        qry->upsertClause = transformUpsertClause(pstate, stmt->upsertClause, stmt->relation);
+    }
+
     /*
      * If we have a RETURNING clause, we need to add the target relation to
      * the query namespace before processing it, so that Var references in
@@ -1480,6 +1509,153 @@ static Query* transformInsertStmt(ParseState* pstate, InsertStmt* stmt)
     return qry;
 }
 
+static void checkUpsertTargetlist(Relation targetTable, List* updateTlist)
+{
+    List* index_list = RelationGetIndexInfoList(targetTable);
+    if (check_unique_constraint(index_list)) {
+        ListCell* target = NULL;
+        ListCell* index = NULL;
+        IndexInfo* index_info = NULL;
+        Bitmapset* target_attrs = NULL; /* attr bitmap according to targetlist */
+        Bitmapset* index_attrs = NULL; /* attr bitmap according to index */
+        TargetEntry* tle = NULL;
+
+        foreach (target, updateTlist) {
+            tle = (TargetEntry*)lfirst(target);
+            target_attrs = bms_add_member(target_attrs, tle->resno);
+        }
+
+        foreach (index, index_list) {
+            index_info = (IndexInfo*)lfirst(index);
+            for (int i = 0; i < index_info->ii_NumIndexAttrs; i++) {
+                int attrno = index_info->ii_KeyAttrNumbers[i];
+
+                if (attrno > 0) {
+                    index_attrs = bms_add_member(index_attrs, attrno);
+                }
+            }
+        }
+
+        if (bms_overlap(index_attrs, target_attrs)) {
+            ereport(ERROR, ((errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+                         errmsg("INSERT ON DUPLICATE KEY UPDATE don't allow update on primary key or unique key."))));
+        }
+    }
+}
+
+List* BuildExcludedTargetlist(Relation targetrel, Index exclRelIndex)
+{
+    List* result = NIL;
+    int attno;
+    Var* var;
+    TargetEntry* te;
+
+    /*
+     * Note that resnos of the tlist must correspond to attnos of the
+     * underlying relation, hence we need entries for dropped columns too.
+     */
+    for (attno = 0; attno < RelationGetNumberOfAttributes(targetrel); attno++) {
+        Form_pg_attribute attr = targetrel->rd_att->attrs[attno];
+        char* name;
+
+        if (attr->attisdropped) {
+            /*
+             * can't use atttypid here, but it doesn't really matter what type
+             * the Const claims to be.
+             */
+            var = (Var*)makeNullConst(INT4OID, -1, InvalidOid);
+            name = NULL;
+        } else {
+            var = makeVar(exclRelIndex, attno + 1, attr->atttypid, attr->atttypmod,
+                          attr->attcollation, 0);
+            name = pstrdup(NameStr(attr->attname));
+        }
+
+        te = makeTargetEntry((Expr*)var, attno + 1, name, false);
+
+        result = lappend(result, te);
+    }
+
+    /*
+     * Add a whole-row-Var entry to support references to "EXCLUDED.*".  Like
+     * the other entries in the EXCLUDED tlist, its resno must match the Var's
+     * varattno, else the wrong things happen while resolving references in
+     * setrefs.c.  This is against normal conventions for targetlists, but
+     * it's okay since we don't use this as a real tlist.
+     */
+    var = makeVar(exclRelIndex, InvalidAttrNumber, targetrel->rd_rel->reltype,
+                  -1, InvalidOid, 0);
+    te = makeTargetEntry((Expr*)var, InvalidAttrNumber, NULL, true);
+    result = lappend(result, te);
+
+    return result;
+}
+
+static UpsertExpr* transformUpsertClause(ParseState* pstate, UpsertClause* upsertClause, RangeVar* relation)
+{
+    UpsertExpr* result = NULL;
+    List* updateTlist = NIL;
+    RangeTblEntry* exclRte = NULL;
+    int exclRelIndex = 0;
+    List* exclRelTlist = NIL;
+    UpsertAction action = UPSERT_NOTHING;
+    Relation targetrel = pstate->p_target_relation;
+
+#ifdef ENABLE_MULTIPLE_NODES
+    if (targetrel->rd_rel->relhastriggers) {
+        ereport(WARNING,
+            (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+             errmsg("INSERT ON DUPLICATE KEY UPDATE will ignore triggers.")));
+    }
+#endif
+
+    if (upsertClause->targetList != NIL) {
+        pstate->p_is_insert = false;
+        action = UPSERT_UPDATE;
+        exclRte = addRangeTableEntryForRelation(pstate, targetrel, makeAlias("excluded", NIL), false, false);
+        exclRte->isexcluded = true;
+        exclRelIndex = list_length(pstate->p_rtable);
+
+        /*
+         * Build a targetlist for the EXCLUDED pseudo relation. Out of
+         * simplicity we do that here, because expandRelAttrs() happens to
+         * nearly do the right thing; specifically it also works with views.
+         * It'd be more proper to instead scan some pseudo scan node, but it
+         * doesn't seem worth the amount of code required.
+         *
+         * The only caveat of this hack is that the permissions expandRelAttrs
+         * adds have to be reset. markVarForSelectPriv() will add the exact
+         * required permissions back.
+         */
+
+        exclRelTlist = BuildExcludedTargetlist(targetrel, exclRelIndex);
+        exclRte->requiredPerms = 0;
+        exclRte->selectedCols = NULL;
+
+        /*
+         * Add EXCLUDED and the target RTE to the namespace, so that they can
+         * be used in the UPDATE statement.
+         */
+        addRTEtoQuery(pstate, exclRte, false, true, true);
+        addRTEtoQuery(pstate, pstate->p_target_rangetblentry, false, true, true);
+
+        updateTlist = transformTargetList(pstate, upsertClause->targetList);
+        updateTlist = transformUpdateTargetList(pstate, updateTlist, upsertClause->targetList, relation);
+        /* We can't update primary or unique key in upsert, check it here */
+        if (IS_PGXC_COORDINATOR || IS_SINGLE_NODE) {
+            checkUpsertTargetlist(pstate->p_target_relation, updateTlist);
+        }
+    }
+
+    /* Finally, build DUPLICATE KEY UPDATE [NOTHING | ... ] expression */
+    result = makeNode(UpsertExpr);
+    result->updateTlist = updateTlist;
+    result->exclRelIndex = exclRelIndex;
+    result->exclRelTlist = exclRelTlist;
+    result->upsertAction = action;
+    return result;
+}
+
 /*
  * Prepare an INSERT row for assignment to the target table.
  *
@@ -2656,13 +2832,10 @@ void fixResTargetListWithTableNameRef(Relation rd, RangeVar* rel, List* clause_l
 static Query* transformUpdateStmt(ParseState* pstate, UpdateStmt* stmt)
 {
     Query* qry = makeNode(Query);
-    RangeTblEntry* target_rte = NULL;
     Node* qual = NULL;
-    ListCell* origTargetList = NULL;
-    ListCell* tl = NULL;
 
     qry->commandType = CMD_UPDATE;
-    pstate->p_is_update = true;
+    pstate->p_is_insert = false;
 
     /* set io state for backend status for the thread, we will use it to check user space */
     pgstat_set_io_state(IOSTATE_READ);
@@ -2714,7 +2887,6 @@ static Query* transformUpdateStmt(ParseState* pstate, UpdateStmt* stmt)
     transformFromClause(pstate, stmt->fromClause);
 
     qry->targetList = transformTargetList(pstate, stmt->targetList);
-
     qual = transformWhereClause(pstate, stmt->whereClause, "WHERE");
 
     qry->returningList = transformReturningList(pstate, stmt->returningList);
@@ -2752,6 +2924,24 @@ static Query* transformUpdateStmt(ParseState* pstate, UpdateStmt* stmt)
      * Now we are done with SELECT-like processing, and can get on with
      * transforming the target list to match the UPDATE target columns.
      */
+    qry->targetList = transformUpdateTargetList(pstate, qry->targetList, stmt->targetList, stmt->relation);
+
+    assign_query_collations(pstate, qry);
+    return qry;
+}
+
+/*
+ * transformUpdateTargetList -
+ * handle SET clause in UPDATE/INSERT ... DUPLICATE KEY UPDATE
+ */
+static List* transformUpdateTargetList(ParseState* pstate, List* qryTlist, List* origTlist, RangeVar* stmtrel)
+{
+    List* tlist = NIL;
+    RangeTblEntry* target_rte = NULL;
+    ListCell* orig_tl = NULL;
+    ListCell* tl = NULL;
+
+    tlist = qryTlist;
 
     /* Prepare to assign non-conflicting resnos to resjunk attributes */
     if (pstate->p_next_resno <= pstate->p_target_relation->rd_rel->relnatts) {
@@ -2760,9 +2950,9 @@ static Query* transformUpdateStmt(ParseState* pstate, UpdateStmt* stmt)
 
     /* Prepare non-junk columns for assignment to target table */
     target_rte = pstate->p_target_rangetblentry;
-    origTargetList = list_head(stmt->targetList);
+    orig_tl = list_head(origTlist);
 
-    foreach (tl, qry->targetList) {
+    foreach (tl, tlist) {
         TargetEntry* tle = (TargetEntry*)lfirst(tl);
         ResTarget* origTarget = NULL;
         int attrno;
@@ -2778,14 +2968,16 @@ static Query* transformUpdateStmt(ParseState* pstate, UpdateStmt* stmt)
             tle->resname = NULL;
             continue;
         }
-        if (origTargetList == NULL) {
+
+        if (orig_tl == NULL) {
             ereport(ERROR,
                 (errcode(ERRCODE_UNEXPECTED_NULL_VALUE), errmsg("UPDATE target count mismatch --- internal error")));
         }
-        origTarget = (ResTarget*)lfirst(origTargetList);
+        origTarget = (ResTarget*)lfirst(orig_tl);
         AssertEreport(IsA(origTarget, ResTarget), MOD_OPT, "Node type inconsistant here");
-
-        fixResTargetNameWithTableNameRef(pstate->p_target_relation, stmt->relation, origTarget);
+        if (stmtrel != NULL) {
+            fixResTargetNameWithTableNameRef(pstate->p_target_relation, stmtrel, origTarget);
+        }
 
         attrno = attnameAttNum(pstate->p_target_relation, origTarget->name, true);
         if (attrno == InvalidAttrNumber) {
@@ -2812,16 +3004,14 @@ static Query* transformUpdateStmt(ParseState* pstate, UpdateStmt* stmt)
         /* Mark the target column as requiring update permissions */
         target_rte->updatedCols = bms_add_member(target_rte->updatedCols, attrno - FirstLowInvalidHeapAttributeNumber);
 
-        origTargetList = lnext(origTargetList);
+        orig_tl = lnext(orig_tl);
     }
-    if (origTargetList != NULL) {
+    if (orig_tl != NULL) {
         ereport(
             ERROR, (errcode(ERRCODE_NOT_NULL_VIOLATION), errmsg("UPDATE target count mismatch --- internal error")));
     }
 
-    assign_query_collations(pstate, qry);
-
-    return qry;
+    return tlist;
 }
 
 /*
diff --git a/src/common/backend/parser/gram.y b/src/common/backend/parser/gram.y
index 1a5359b9c..5ae5fb271 100755
--- a/src/common/backend/parser/gram.y
+++ b/src/common/backend/parser/gram.y
@@ -239,6 +239,7 @@ static void ParseUpdateMultiSet(List *set_target_list, SelectStmt *stmt, core_yy
 /* PGXC_END */
     ForeignPartState    *foreignpartby;
 	MergeWhenClause		*mergewhen;
+	UpsertClause *upsert;
 }
 
 %type <node>	stmt schema_stmt
@@ -447,7 +448,7 @@ static void ParseUpdateMultiSet(List *set_target_list, SelectStmt *stmt, core_yy
 
 /* INSERT */
 %type <istmt>	insert_rest
-%type <node>	duplicate_update_clause
+%type <node>   upsert_clause
 
 %type <mergewhen>	merge_insert merge_update
 
@@ -13067,80 +13068,79 @@ InsertStmt: opt_with_clause INSERT INTO qualified_name insert_rest returning_cla
 				$5->withClause = $1;
 				$$ = (Node *) $5;
 			}
-			| opt_with_clause INSERT INTO qualified_name insert_rest duplicate_update_clause returning_clause
+			| opt_with_clause INSERT INTO qualified_name insert_rest upsert_clause returning_clause
 				{
-					/* It is a INSERT ON DUPLICATE KEY UPDATE statement */
-					if ($7 != NIL)
-					{
+					if ($7 != NIL) {
 						ereport(ERROR,
 							(errmodule(MOD_PARSER),
 							 errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 							 errmsg("RETURNING clause is not yet supported whithin INSERT ON DUPLICATE KEY UPDATE statement.")));
 					}
-					if ($1 != NULL)
-					{
+					if ($1 != NULL) {
 						ereport(ERROR,
 								(errmodule(MOD_PARSER),
 								 errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 								 errmsg("WITH clause is not yet supported whithin INSERT ON DUPLICATE KEY UPDATE statement.")));
 					}
 
-					if ($5 != NULL && $5->cols != NIL)
-					{
-						ListCell *c = NULL;
-						List *cols = $5->cols;
-						foreach (c, cols)
-						{
-							ResTarget *rt = (ResTarget *)lfirst(c);
-							if (rt->indirection != NIL)
-							{
-								ereport(ERROR,
-									(errmodule(MOD_PARSER),
-									 errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-									 errmsg("Subfield name or array subscript of column \"%s\" "
-										"is not yet supported whithin INSERT ON DUPLICATE KEY UPDATE statement.",
-										rt->name),
-									 errhint("Try assign a composite or an array expression to column \"%s\".", rt->name)));
+					if (unlikely(u_sess->attr.attr_sql.enable_upsert_to_merge)) {
+
+						if ($5 != NULL && $5->cols != NIL) {
+							ListCell *c = NULL;
+							List *cols = $5->cols;
+							foreach (c, cols) {
+								ResTarget *rt = (ResTarget *)lfirst(c);
+								if (rt->indirection != NIL) {
+									ereport(ERROR,
+										(errmodule(MOD_PARSER),
+										 errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+										 errmsg("Subfield name or array subscript of column \"%s\" "
+											"is not yet supported whithin INSERT ON DUPLICATE KEY UPDATE statement.",
+											rt->name),
+										 errhint("Try assign a composite or an array expression to column \"%s\".", rt->name)));
+								}
 							}
 						}
+
+						MergeStmt *m = makeNode(MergeStmt);
+						m->is_insert_update = true;
+
+						/* for UPSERT, keep the INSERT statement as well */
+						$5->relation = $4;
+						$5->returningList = $7;
+						$5->withClause = $1;
+						m->insert_stmt = (Node *) copyObject($5);
+
+						/* fill a MERGE statement*/
+						m->relation = $4;
+
+						Alias *a1 = makeAlias(($4->relname), NIL);
+						$4->alias = a1;
+
+						Alias *a2 = makeAlias("excluded", NIL);
+						RangeSubselect *r = makeNode(RangeSubselect);
+						r->alias = a2;
+						r->subquery = (Node *) ($5->selectStmt);
+						m->source_relation = (Node *) r;
+
+						MergeWhenClause *n = makeNode(MergeWhenClause);
+						n->matched = false;
+						n->commandType = CMD_INSERT;
+						n->cols = $5->cols;
+						n->values = NULL;
+
+						m->mergeWhenClauses = list_make1((Node *) n);
+						if ($6 != NULL)
+							m->mergeWhenClauses = list_concat(list_make1($6), m->mergeWhenClauses);
+
+						$$ = (Node *)m;
+					} else {
+						$5->relation = $4;
+						$5->returningList = $7;
+						$5->withClause = $1;
+						$5->upsertClause = (UpsertClause *)$6;
+						$$ = (Node *) $5;
 					}
-
-					MergeStmt *m = makeNode(MergeStmt);
-					m->is_insert_update = true;
-
-					/* for UPSERT, keep the INSERT statement as well */
-					$5->relation = $4;
-					$5->returningList = $7;
-					$5->withClause = $1;
-					m->insert_stmt = (Node *) copyObject($5);
-
-					/* fill a MERGE statement*/
-					m->relation = $4;
-
-					Alias *a1 = makeAlias(($4->relname), NIL);
-					$4->alias = a1;
-
-					Alias *a2 = makeAlias("__unnamed_subquery_source__", NIL);
-					RangeSubselect *r = makeNode(RangeSubselect);
-					r->alias = a2;
-					r->subquery = (Node *) ($5->selectStmt);
-					m->source_relation = (Node *) r;
-
-					MergeWhenClause *n = makeNode(MergeWhenClause);
-					n->matched = false;
-					n->commandType = CMD_INSERT;
-					n->cols = $5->cols;
-					n->values = NULL;
-
-					m->mergeWhenClauses = list_make2(($6), (Node *) n);
-
-					/* for UPSERT, keep the INSERT statement as well */
-					$5->relation = $4;
-					$5->returningList = $7;
-					$5->withClause = $1;
-					m->insert_stmt = (Node *) copyObject($5);
-
-					$$ = (Node *)m;
 				}
 		;
 
@@ -13188,16 +13188,47 @@ returning_clause:
 			| /* EMPTY */				{ $$ = NIL; }
 		;
 
-duplicate_update_clause:
-            ON DUPLICATE KEY UPDATE set_clause_list
-                {
-                    MergeWhenClause *n = makeNode(MergeWhenClause);
-                    n->matched = true;
-                    n->commandType = CMD_UPDATE;
-                    n->targetList = $5;
-                    $$ = (Node *) n;
-                }
-        ;
+upsert_clause:
+			ON DUPLICATE KEY UPDATE set_clause_list
+				{
+					if (unlikely(u_sess->attr.attr_sql.enable_upsert_to_merge)) {
+						MergeWhenClause *n = makeNode(MergeWhenClause);
+						n->matched = true;
+						n->commandType = CMD_UPDATE;
+						n->targetList = $5;
+						$$ = (Node *) n;
+					} else {
+						/* check subquery in set clause*/
+						ListCell* cell = NULL;
+						ResTarget* res = NULL;
+						foreach (cell, $5) {
+							res = (ResTarget*)lfirst(cell);
+							if (IsA(res->val,SubLink)) {
+								ereport(ERROR,
+									(errmodule(MOD_PARSER),
+									 errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+									 errmsg("Update with subquery is not yet supported whithin INSERT ON DUPLICATE KEY UPDATE statement.")));
+							}
+						}
+
+						UpsertClause *uc = makeNode(UpsertClause);
+						uc->targetList = $5;
+						uc->location = @1;
+						$$ = (Node *) uc;
+					}
+				}
+			| ON DUPLICATE KEY UPDATE NOTHING
+				{
+					if (unlikely(u_sess->attr.attr_sql.enable_upsert_to_merge)) {
+						$$ = NULL;
+					} else {
+						UpsertClause *uc = makeNode(UpsertClause);
+						uc->targetList = NIL;
+						uc->location = @1;
+						$$ = (Node *) uc;
+					}
+				}
+			;
 
 /*****************************************************************************
  *
@@ -13288,7 +13319,7 @@ UpdateStmt: opt_with_clause UPDATE relation_expr_opt_alias
 				{
 					UpdateStmt *n = makeNode(UpdateStmt);
 					n->relation = $3;
-                    n->targetList = $5;
+					n->targetList = $5;
 					n->fromClause = $6;
 					n->whereClause = $7;
 					n->returningList = $8;
@@ -13313,6 +13344,30 @@ single_set_clause:
 					$$ = $1;
 					$$->val = (Node *) $3;
 				}
+			/* this is only used in ON DUPLICATE KEY UPDATE col = VALUES(col) case
+			 * for mysql compatibility
+			 */
+			| set_target '=' VALUES '(' columnref ')'
+				{
+					ColumnRef *c = NULL;
+					int nfields = 0;
+					if (IsA($5, ColumnRef)) {
+						c = (ColumnRef *) $5;
+					} else if (IsA($5, A_Indirection)) {
+						c = (ColumnRef *)(((A_Indirection *)$5)->arg);
+					}
+					nfields = list_length(c->fields);
+					/* only allow col.*, col[...], col */
+					if (nfields > 1) {
+						ereport(ERROR,
+							(errcode(ERRCODE_SYNTAX_ERROR),
+							 errmsg("only allow column name within VALUES"), parser_errposition(@5)));
+					}
+
+					c->fields = lcons((Node *)makeString("excluded"), c->fields);
+					$$ = $1;
+					$$->val = (Node *) $5;
+				}
 		;
 
 multiple_set_clause:
diff --git a/src/common/backend/parser/parse_collate.cpp b/src/common/backend/parser/parse_collate.cpp
index 315f5ceb3..87584a22f 100755
--- a/src/common/backend/parser/parse_collate.cpp
+++ b/src/common/backend/parser/parse_collate.cpp
@@ -459,8 +459,8 @@ static bool assign_collations_walker(Node* node, assign_collations_context* cont
         case T_FromExpr:
         case T_SortGroupClause:
         case T_MergeAction:
+        case T_UpsertExpr:
             (void)expression_tree_walker(node, (bool (*)())assign_collations_walker, (void*)&loccontext);
-
             /*
              * When we're invoked on a query's jointree, we don't need to do
              * anything with join nodes except recurse through them to process
@@ -786,4 +786,4 @@ static void assign_ordered_set_collations(Aggref* aggref, assign_collations_cont
             assign_expr_collations(loccontext->pstate, (Node*)tle);
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/common/backend/parser/parse_merge.cpp b/src/common/backend/parser/parse_merge.cpp
index bc054149b..ed6442efd 100644
--- a/src/common/backend/parser/parse_merge.cpp
+++ b/src/common/backend/parser/parse_merge.cpp
@@ -56,7 +56,8 @@ static void check_system_column_node(Node* node, bool is_insert_update);
 static void check_system_column_reference(List* joinVarList, List* mergeActionList, bool is_insert_update);
 static void checkTargetTableSystemCatalog(Relation targetRel);
 static void check_insert_action_targetlist(List* merge_action_list, List* source_targetlist);
-static bool check_unique_constraint(List*& index_list);
+static bool check_update_action_targetlist(List* update_action_list, List* source_targetlist);
+bool check_unique_constraint(List*& index_list);
 static bool find_valid_unique_constraint(Relation relation, List* colnames, List*& index_list);
 static bool var_in_list(Var* var, List* list);
 static Bitmapset* get_relation_attno_bitmap_by_names(Relation relation, List* colnames);
@@ -1180,6 +1181,16 @@ Query* transformMergeStmt(ParseState* pstate, MergeStmt* stmt)
         Assert(stmt->insert_stmt != NULL);
         Assert(IsA(stmt->insert_stmt, InsertStmt));
 
+        if (check_update_action_targetlist(mergeActionList, qry->mergeSourceTargetList)) {
+            if (u_sess->attr.attr_sql.enable_upsert_to_merge) {
+                return qry;
+            }
+            ereport(ERROR,
+                (errcode(ERRCODE_UNDEFINED_COLUMN),
+                    errmsg("Invalid column reference in the UPDATE target values"),
+                    errhint("Only allow to reference target table's column in the UPDATE clause")));
+        }
+
         Query* insert_query = NULL;
         ParseState* insert_pstate = make_parsestate(NULL);
         insert_pstate->p_resolve_unknowns = pstate->p_resolve_unknowns;
@@ -1768,7 +1779,7 @@ static int count_target_columns(Node* query)
  * @out index_list: unique index list
  * @return: true if there is any primary or unique index
  */
-static bool check_unique_constraint(List*& index_list)
+bool check_unique_constraint(List*& index_list)
 {
     /* There are no indexes */
     if (index_list == NIL) {
@@ -1790,10 +1801,48 @@ static bool check_unique_constraint(List*& index_list)
     return true;
 }
 
+bool check_action_targetlist_condition(List* action_targetlist, List* source_targetlist, bool condition_in)
+{
+    ListCell* var_cell = NULL;
+    /* oops, not insert action found, noting to do */
+    if (action_targetlist == NIL) {
+        return true;
+    }
+    /* let's do the hard work */
+    List* vars_list =
+        pull_var_clause((Node*)action_targetlist, PVC_RECURSE_AGGREGATES, PVC_RECURSE_PLACEHOLDERS);
+    List* source_vars_list =
+        pull_var_clause((Node*)source_targetlist, PVC_RECURSE_AGGREGATES, PVC_RECURSE_PLACEHOLDERS);
+    foreach (var_cell, vars_list) {
+        Var* var = (Var*)lfirst(var_cell);
+        if (var_in_list(var, source_vars_list) != condition_in) {
+            return false;
+        }
+    }
+    return true;
+}
+
+bool check_update_action_targetlist(List* merge_action_list, List* source_targetlist)
+{
+    ListCell* action_cell = NULL;
+    List* update_action_targetlist = NIL;
+
+    /* first let's locate the insert action */
+    foreach (action_cell, merge_action_list) {
+        MergeAction* action = (MergeAction*)lfirst(action_cell);
+        if (action->commandType == CMD_UPDATE) {
+            update_action_targetlist = action->targetList;
+
+            break;
+        }
+    }
+
+    return !check_action_targetlist_condition(update_action_targetlist, source_targetlist, false);
+}
+
 /* report error if vars in insert_action_targetlist not found in source_targetlist */
 void check_insert_action_targetlist(List* merge_action_list, List* source_targetlist)
 {
-    ListCell* var_cell = NULL;
     ListCell* action_cell = NULL;
     List* insert_action_targetlist = NIL;
 
@@ -1806,25 +1855,10 @@ void check_insert_action_targetlist(List* merge_action_list, List* source_target
             break;
         }
     }
-
-    /* oops, not insert action found, noting to do */
-    if (insert_action_targetlist == NIL) {
-        return;
-    }
-    /* let's do the hard work */
-    List* insert_vars_list =
-        pull_var_clause((Node*)insert_action_targetlist, PVC_RECURSE_AGGREGATES, PVC_RECURSE_PLACEHOLDERS);
-    List* source_vars_list =
-        pull_var_clause((Node*)source_targetlist, PVC_RECURSE_AGGREGATES, PVC_RECURSE_PLACEHOLDERS);
-    foreach (var_cell, insert_vars_list) {
-        Var* var = (Var*)lfirst(var_cell);
-
-        /* INSERT can only reference source rel's targetlist */
-        if (!var_in_list(var, source_vars_list)) {
-            ereport(ERROR,
-                (errcode(ERRCODE_UNDEFINED_COLUMN),
-                    errmsg("Invalid column reference in the INSERT VALUES Clause"),
-                    errhint("You may have referenced target table's column")));
-        }
+    if (!check_action_targetlist_condition(insert_action_targetlist, source_targetlist, true)) {
+        ereport(ERROR,
+            (errcode(ERRCODE_UNDEFINED_COLUMN),
+                errmsg("Invalid column reference in the INSERT VALUES Clause"),
+                errhint("You may have referenced target table's column")));
     }
 }
diff --git a/src/common/backend/parser/parse_relation.cpp b/src/common/backend/parser/parse_relation.cpp
index cc2c863b4..45d9960e8 100755
--- a/src/common/backend/parser/parse_relation.cpp
+++ b/src/common/backend/parser/parse_relation.cpp
@@ -479,7 +479,7 @@ CommonTableExpr* GetCTEForRTE(ParseState* pstate, RangeTblEntry* rte, int rtelev
  * Side effect: if we find a match, mark the RTE as requiring read access
  * for the column.
  */
-Node* scanRTEForColumn(ParseState* pstate, RangeTblEntry* rte, char* colname, int location)
+Node* scanRTEForColumn(ParseState* pstate, RangeTblEntry* rte, char* colname, int location, bool omit_excluded)
 {
     Node* result = NULL;
     int attnum = 0;
@@ -501,6 +501,9 @@ Node* scanRTEForColumn(ParseState* pstate, RangeTblEntry* rte, char* colname, in
      */
     foreach (c, rte->eref->colnames) {
         attnum++;
+        if (omit_excluded && rte->isexcluded) {
+            continue;
+        }
         if (strcmp(strVal(lfirst(c)), colname) == 0) {
             if (result != NULL) {
                 ereport(ERROR,
@@ -607,7 +610,7 @@ Node* colNameToVar(ParseState* pstate, char* colname, bool localonly, int locati
             Node* newresult = NULL;
 
             /* use orig_pstate here to get the right sublevels_up */
-            newresult = scanRTEForColumn(orig_pstate, rte, colname, location);
+            newresult = scanRTEForColumn(orig_pstate, rte, colname, location, true);
             if (newresult != NULL) {
                 if (final_rte != NULL) {
                     *final_rte = rte;
@@ -1087,6 +1090,7 @@ RangeTblEntry* addRangeTableEntry(ParseState* pstate, RangeVar* relation, Alias*
 
     rte->rtekind = RTE_RELATION;
     rte->alias = alias;
+    rte->isexcluded = false;
 
     if (pstate == NULL) {
         ereport(ERROR, (errmodule(MOD_OPT), errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED), errmsg("pstate can not be NULL")));
@@ -1205,6 +1209,7 @@ RangeTblEntry* addRangeTableEntryForRelation(ParseState* pstate, Relation rel, A
     rte->relkind = rel->rd_rel->relkind;
     rte->ispartrel = RELATION_IS_PARTITIONED(rel);
 	rte->relhasbucket = RELATION_HAS_BUCKET(rel);
+    rte->isexcluded = false;
     /*
      * In cases that target relation's rd_refSynOid is valid, it has been referenced from one synonym.
      * thus, alias name is used to take its raw relname away in order to form the refname.
diff --git a/src/common/backend/parser/parse_target.cpp b/src/common/backend/parser/parse_target.cpp
index 144ae7abd..34154c148 100755
--- a/src/common/backend/parser/parse_target.cpp
+++ b/src/common/backend/parser/parse_target.cpp
@@ -335,12 +335,12 @@ static void markTargetListOrigin(ParseState* pstate, TargetEntry* tle, Var* var,
 
 /*
  * transformAssignedExpr()
- *	This is used in INSERT and UPDATE statements only.	It prepares an
- *	expression for assignment to a column of the target table.
- *	This includes coercing the given value to the target column's type
- *	(if necessary), and dealing with any subfield names or subscripts
- *	attached to the target column itself.  The input expression has
- *	already been through transformExpr().
+ *	This is used in INSERT and UPDATE (including DUPLICATE KEY UPDATE)
+ *	statements only. It prepares an expression for assignment to a column
+ *	of the target table. This includes coercing the given value
+ *	to the target column's type (if necessary), and dealing with
+ *	any subfield names or subscripts attached to the target column itself
+ *	The input expression has already been through transformExpr().
  *
  * pstate		parse state
  * expr			expression to be modified
@@ -496,11 +496,11 @@ Expr* transformAssignedExpr(ParseState* pstate, Expr* expr, char* colname, int a
 
 /*
  * updateTargetListEntry()
- *	This is used in UPDATE statements only. It prepares an UPDATE
- *	TargetEntry for assignment to a column of the target table.
- *	This includes coercing the given value to the target column's type
- *	(if necessary), and dealing with any subfield names or subscripts
- *	attached to the target column itself.
+ *	This is used in UPDATE (and DUPLICATE KEY UPDATE) statements only.
+ *	It prepares an UPDATE TargetEntry for assignment to a column of
+ *	the target table. This includes coercing the given value to the
+ *	target column's type (if necessary), and dealing with any subfield
+ *	names or subscripts attached to the target column itself.
  *
  * pstate		parse state
  * tle			target list entry to be modified
diff --git a/src/common/backend/utils/adt/ruleutils.cpp b/src/common/backend/utils/adt/ruleutils.cpp
index f382978ca..5eec70022 100755
--- a/src/common/backend/utils/adt/ruleutils.cpp
+++ b/src/common/backend/utils/adt/ruleutils.cpp
@@ -222,6 +222,8 @@ static void get_with_clause(Query* query, deparse_context* context);
 static void get_select_query_def(Query* query, deparse_context* context, TupleDesc resultDesc);
 static void get_insert_query_def(Query* query, deparse_context* context);
 static void get_update_query_def(Query* query, deparse_context* context);
+static void get_update_query_targetlist_def(
+    Query* query, List* targetList, RangeTblEntry* rte, deparse_context* context);
 static void get_delete_query_def(Query* query, deparse_context* context);
 static void get_utility_query_def(Query* query, deparse_context* context);
 static void get_basic_select_query(Query* query, deparse_context* context, TupleDesc resultDesc);
@@ -3738,6 +3740,10 @@ static void set_deparse_planstate(deparse_namespace* dpns, PlanState* ps)
      * For a SubqueryScan, pretend the subplan is INNER referent.  (We don't
      * use OUTER because that could someday conflict with the normal meaning.)
      * Likewise, for a CteScan, pretend the subquery's plan is INNER referent.
+     * For DUPLICATE KEY UPDATE we just need the inner tlist to point to the
+     * excluded expression's tlist. (Similar to the SubqueryScan we don't want
+     * to reuse OUTER, it's used for RETURNING in some modify table cases,
+     * although not INSERT ... ON DUPLICATE KEY UPDATE).
      */
     if (IsA(ps, SubqueryScanState))
         dpns->inner_planstate = ((SubqueryScanState*)ps)->subplan;
@@ -3749,6 +3755,7 @@ static void set_deparse_planstate(deparse_namespace* dpns, PlanState* ps)
         ModifyTableState* mps = (ModifyTableState*)ps;
         dpns->outer_planstate = mps->mt_plans[0];
 
+        dpns->inner_planstate = ps;
         /*
          * For merge into, we should deparse the inner plan,  since the targetlist and qual will
          * reference sourceTargetList, which comes from outer plan of the join (source table)
@@ -3762,7 +3769,9 @@ static void set_deparse_planstate(deparse_namespace* dpns, PlanState* ps)
     } else
         dpns->inner_planstate = innerPlanState(ps);
 
-    if (dpns->inner_planstate != NULL)
+    if (IsA(ps, ModifyTableState))
+        dpns->inner_tlist = ((ModifyTableState*)ps)->mt_upsert->us_excludedtlist;
+    else if (dpns->inner_planstate != NULL)
         dpns->inner_tlist = dpns->inner_planstate->plan->targetlist;
     else
         dpns->inner_tlist = NIL;
@@ -5564,18 +5573,9 @@ static void get_insert_query_def(Query* query, deparse_context* context)
     }
 
     /*
-     * select_rte and values_rte are not required by INSERT queries in XC
-     * Both these should stay null for INSERT queries to work corretly
-     * Consider an example
-     * create table tt as values(1,'One'),(2,'Two');
-     * This query uses values_rte, but we do not need them in XC
-     * because it gets broken down into two queries
-     * CREATE TABLE tt(column1 int4, column2 text)
-     * and
-     * INSERT INTO tt (column1, column2) VALUES ($1, $2)
-     * Note that the insert query does not need values_rte
-     *
-     * Now consider another example
+     * select_rte are not required by INSERT queries in XC
+     * it should stay null for INSERT queries to work corretly
+     * consider an example
      * insert into tt select * from tt
      * This query uses select_rte, but again that is not required in XC
      * Again here the query gets broken down into two queries
@@ -5600,7 +5600,35 @@ static void get_insert_query_def(Query* query, deparse_context* context)
                 }
                 select_rte = rte;
             }
+        }
 
+#ifdef PGXC
+    }
+#endif
+
+    /*
+     * values_rte will be required by INSERT queries in XC
+     * only when the relation is located on a single node
+     * requested by FQS
+     * Consider an example
+     * CREATE NODE GROUP ng WITH (datanode2);
+     * CREATE TABLE tt (column1 int4, column2 text) TO GROUP ng;
+     * INSERT INTO tt (column1) VALUES(1), (2)
+     *
+     * for other cases values_rte should stay null
+     * create table tt as values(1,'One'),(2,'Two');
+     * This query uses values_rte, but we do not need them in XC
+     * because it gets broken down into two queries
+     * CREATE TABLE tt(column1 int4, column2 text)
+     * and
+     * INSERT INTO tt (column1, column2) VALUES ($1, $2)
+     * Note that the insert query does not need values_rte
+     */
+#ifdef PGXC
+    if (context->is_fqs || !(IS_PGXC_COORDINATOR && !IsConnFromCoord())) {
+#endif
+        foreach (l, query->rtable) {
+            rte = (RangeTblEntry*)lfirst(l);
             if (rte->rtekind == RTE_VALUES) {
                 if (values_rte != NULL) {
                     ereport(ERROR, (errcode(ERRCODE_RESTRICT_VIOLATION), errmsg("too many values RTEs in INSERT")));
@@ -5611,6 +5639,7 @@ static void get_insert_query_def(Query* query, deparse_context* context)
 #ifdef PGXC
     }
 #endif
+
     if ((select_rte != NULL) && (values_rte != NULL)) {
         ereport(ERROR, (errcode(ERRCODE_RESTRICT_VIOLATION), errmsg("both subquery and values RTEs in INSERT")));
     }
@@ -5758,21 +5787,37 @@ static void get_insert_query_def(Query* query, deparse_context* context)
         appendStringInfo(buf, "DEFAULT VALUES");
     }
 
-    /* it is an UPSERT statement, add ON DUPLICATE KEY UPDATE expression */
+    /* for MERGE INTO  statement for UPSERT, add ON DUPLICATE KEY UPDATE expression */
     if (query->mergeActionList) {
         appendStringInfo(buf, " ON DUPLICATE KEY UPDATE ");
 
         ListCell* l = NULL;
+        bool update = false;
         foreach (l, query->mergeActionList) {
             MergeAction* mc = (MergeAction*)lfirst(l);
 
             /* only deparse the update clause */
             if (mc->commandType == CMD_UPDATE) {
+                update = true;
                 get_set_target_list(mc->targetList, rte, context);
             } else {
                 continue;
             }
         }
+        if (!update) {
+            appendStringInfoString(buf, "NOTHING");
+        }
+    }
+
+    /* for INSERT statement for UPSERT, add ON DUPLICATE KEY UPDATE expression */
+    if (query->upsertClause != NULL && query->upsertClause->upsertAction != UPSERT_NONE) {
+        appendStringInfoString(buf, " ON DUPLICATE KEY UPDATE ");
+        UpsertExpr* upsertClause = query->upsertClause;
+        if (upsertClause->upsertAction == UPSERT_NOTHING) {
+            appendStringInfoString(buf, "NOTHING");
+        } else {
+            get_update_query_targetlist_def(query, upsertClause->updateTlist, rte, context);
+        }
     }
 
     /* Add RETURNING if present */
@@ -5789,9 +5834,7 @@ static void get_insert_query_def(Query* query, deparse_context* context)
 static void get_update_query_def(Query* query, deparse_context* context)
 {
     StringInfo buf = context->buf;
-    char* sep = NULL;
     RangeTblEntry* rte = NULL;
-    ListCell* l = NULL;
 
     /* Insert the WITH clause if given */
     get_with_clause(query, context);
@@ -5810,10 +5853,38 @@ static void get_update_query_def(Query* query, deparse_context* context)
         appendStringInfo(buf, " %s", quote_identifier(rte->alias->aliasname));
     }
     appendStringInfoString(buf, " SET ");
+    /* Deparse targetlist */
+    get_update_query_targetlist_def(query, query->targetList, rte, context);
 
+    /* Add the FROM clause if needed */
+    get_from_clause(query, " FROM ", context);
+
+    /* Add a WHERE clause if given */
+    if (query->jointree->quals != NULL) {
+        append_context_keyword(context, " WHERE ", PRETTYINDENT_STD, PRETTYINDENT_STD, 1);
+        get_rule_expr(query->jointree->quals, context, false);
+    }
+
+    /* Add RETURNING if present */
+    if (query->returningList) {
+        append_context_keyword(context, " RETURNING", PRETTYINDENT_STD, PRETTYINDENT_STD, 1);
+        get_target_list(query, query->returningList, context, NULL);
+    }
+}
+
+/* ----------
+ * get_update_query_targetlist_def         - Parse back an UPDATE targetlist
+ * ----------
+ */
+static void get_update_query_targetlist_def(Query* query, List* targetList,
+    RangeTblEntry* rte, deparse_context* context)
+{
+    StringInfo buf = context->buf;
+    ListCell* l;
+    const char* sep;
     /* Add the comma separated list of 'attname = value' */
     sep = "";
-    foreach (l, query->targetList) {
+    foreach (l, targetList) {
         TargetEntry* tle = (TargetEntry*)lfirst(l);
         Node* expr = NULL;
 
@@ -5890,21 +5961,6 @@ static void get_update_query_def(Query* query, deparse_context* context)
             get_rule_expr((Node*)tle->expr, context, false);
         }
     }
-
-    /* Add the FROM clause if needed */
-    get_from_clause(query, " FROM ", context);
-
-    /* Add a WHERE clause if given */
-    if (query->jointree->quals != NULL) {
-        append_context_keyword(context, " WHERE ", -PRETTYINDENT_STD, PRETTYINDENT_STD, 1);
-        get_rule_expr(query->jointree->quals, context, false);
-    }
-
-    /* Add RETURNING if present */
-    if (query->returningList) {
-        append_context_keyword(context, " RETURNING", -PRETTYINDENT_STD, PRETTYINDENT_STD, 1);
-        get_target_list(query, query->returningList, context, NULL);
-    }
 }
 
 /* ----------
diff --git a/src/common/backend/utils/misc/guc.cpp b/src/common/backend/utils/misc/guc.cpp
index e0d216dea..34a660a5e 100644
--- a/src/common/backend/utils/misc/guc.cpp
+++ b/src/common/backend/utils/misc/guc.cpp
@@ -1389,6 +1389,20 @@ static void init_configure_names_bool()
             NULL,
             NULL
         },
+        {
+            {
+                "enable_upsert_to_merge",
+                PGC_USERSET,
+                QUERY_TUNING_METHOD,
+                gettext_noop("Enable transform INSERT ON DUPLICATE KEY UDPATE statement to MERGE statement."),
+                NULL
+            },
+            &u_sess->attr.attr_sql.enable_upsert_to_merge,
+            false,
+            NULL,
+            NULL,
+            NULL
+        },
 #ifdef ENABLE_MULTIPLE_NODES
         {
             {
diff --git a/src/common/backend/utils/time/tqual.cpp b/src/common/backend/utils/time/tqual.cpp
index 9ecb9446d..57f0c4b39 100755
--- a/src/common/backend/utils/time/tqual.cpp
+++ b/src/common/backend/utils/time/tqual.cpp
@@ -520,6 +520,14 @@ bool HeapTupleSatisfiesToast(HeapTuple htup, Snapshot snapshot, Buffer buffer)
     if (!HeapTupleHeaderXminCommitted(tuple)) {
         if (HeapTupleHeaderXminInvalid(tuple))
             return false;
+
+        /*
+         * An invalid Xmin can be left behind by a speculative insertion that
+         * is cancelled by super-deleting the tuple.  We shouldn't see any of
+         * those in TOAST tables, but better safe than sorry.
+         */
+        if (!TransactionIdIsValid(HeapTupleHeaderGetXmin(BufferGetPage(buffer), tuple)))
+            return false;
     }
 
     /* otherwise assume the tuple is valid for TOAST. */
@@ -552,8 +560,11 @@ bool HeapTupleSatisfiesToast(HeapTuple htup, Snapshot snapshot, Buffer buffer)
  *	the case where the tuple is share-locked by a MultiXact, even if the
  *	MultiXact includes the current transaction.  Callers that want to
  *	distinguish that case must test for it themselves.)
+ *
+ *	HeapTupleSelfCreated: the tuple didn't exist at all when the scan started, it
+ *	was created during the current CommandId (scan)
  */
-HTSU_Result HeapTupleSatisfiesUpdate(HeapTuple htup, CommandId curcid, Buffer buffer)
+HTSU_Result HeapTupleSatisfiesUpdate(HeapTuple htup, CommandId curcid, Buffer buffer, bool self_visible)
 {
     bool needSync = false;
     HeapTupleHeader tuple = htup->t_data;
@@ -580,8 +591,10 @@ restart:
             return HeapTupleInvisible;
 
         if (TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmin(page, tuple))) {
-            if (HeapTupleHeaderGetCmin(tuple, page) >= curcid)
+            if (HeapTupleHeaderGetCmin(tuple, page) > curcid)
                 return HeapTupleInvisible; /* inserted after scan started */
+            else if (HeapTupleHeaderGetCmin(tuple, page) == curcid && !self_visible)
+                return HeapTupleSelfCreated; /* inserted during the scan */
 
             if (tuple->t_infomask & HEAP_XMAX_INVALID) /* xid invalid */
                 return HeapTupleMayBeUpdated;
diff --git a/src/gausskernel/optimizer/commands/copy.cpp b/src/gausskernel/optimizer/commands/copy.cpp
index 5d733e1f3..5c0e74c12 100644
--- a/src/gausskernel/optimizer/commands/copy.cpp
+++ b/src/gausskernel/optimizer/commands/copy.cpp
@@ -3490,7 +3490,7 @@ static uint64 CopyFrom(CopyState cstate)
         1, /* dummy rangetable index */
         0);
 
-    ExecOpenIndices(resultRelInfo);
+    ExecOpenIndices(resultRelInfo, false);
     init_gtt_storage(CMD_INSERT, resultRelInfo);
 
     resultRelationDesc = resultRelInfo->ri_RelationDesc;
@@ -4066,7 +4066,7 @@ static uint64 CopyFrom(CopyState cstate)
                             estate,
                             isPartitionRel ? heaprel : NULL,
                             isPartitionRel ? partition : NULL,
-                            bucketid);
+                            bucketid, NULL);
 
                     /* AFTER ROW INSERT Triggers */
                     ExecARInsertTriggers(estate, resultRelInfo, partitionid, bucketid, tuple, recheckIndexes);
@@ -4413,7 +4413,7 @@ static void CopyFromUpdateIndexAndRunAfterRowTrigger(EState* estate, ResultRelIn
                 estate,
                 ispartitionedtable ? actualHeap : NULL,
                 ispartitionedtable ? partition : NULL,
-                bucketid);
+                bucketid, NULL);
             ExecARInsertTriggers(estate, resultRelInfo, partitionOid, bucketid, bufferedTuples[i], recheckIndexes);
             list_free(recheckIndexes);
         }
@@ -4484,7 +4484,7 @@ static void CopyFromInsertBatch(Relation rel, EState* estate, CommandId mycid, i
                 estate,
                 ispartitionedtable ? actualHeap : NULL,
                 ispartitionedtable ? partition : NULL,
-                bucketId);
+                bucketId, NULL);
             ExecARInsertTriggers(estate, resultRelInfo, partitionOid, bucketId, bufferedTuples[i], recheckIndexes);
             list_free(recheckIndexes);
         }
diff --git a/src/gausskernel/optimizer/commands/explain.cpp b/src/gausskernel/optimizer/commands/explain.cpp
index a627fd21c..1b78fd1e6 100755
--- a/src/gausskernel/optimizer/commands/explain.cpp
+++ b/src/gausskernel/optimizer/commands/explain.cpp
@@ -187,6 +187,7 @@ static void ExplainProperty(const char* qlabel, const char* value, bool numeric,
 static void ExplainOpenGroup(const char* objtype, const char* labelname, bool labeled, ExplainState* es);
 static void ExplainCloseGroup(const char* objtype, const char* labelname, bool labeled, ExplainState* es);
 static void ExplainDummyGroup(const char* objtype, const char* labelname, ExplainState* es);
+static void show_on_duplicate_info(ModifyTableState* mtstate, ExplainState* es);
 #ifdef PGXC
 static void ExplainExecNodes(const ExecNodes* en, ExplainState* es);
 static void ExplainRemoteQuery(RemoteQuery* plan, PlanState* planstate, List* ancestors, ExplainState* es);
@@ -2326,6 +2327,12 @@ static void ExplainNode(
                     }
                 }
             } else {
+                /* upsert cases */
+                ModifyTableState* mtstate = (ModifyTableState*)planstate;
+                if (mtstate->mt_upsert != NULL &&
+                    mtstate->mt_upsert->us_action != UPSERT_NONE && mtstate->resultRelInfo->ri_NumIndices > 0) {
+                    show_on_duplicate_info(mtstate, es);
+                }
                 /* non-merge cases */
                 foreach (elt, mt->remote_plans) {
                     if (lfirst(elt)) {
@@ -7912,6 +7919,39 @@ static void ExplainTargetRel(Plan* plan, Index rti, ExplainState* es)
     }
 }
 
+/*
+ * Show extra information for upsert info
+ */
+static void show_on_duplicate_info(ModifyTableState* mtstate, ExplainState* es)
+{
+    ResultRelInfo* resultRelInfo = mtstate->resultRelInfo;
+    IndexInfo* indexInfo = NULL;
+    List* idxNames = NIL;
+
+    /* Gather names of ON CONFLICT Arbiter indexes */
+    for (int i = 0; i < resultRelInfo->ri_NumIndices; ++i) {
+        indexInfo = resultRelInfo->ri_IndexRelationInfo[i];
+        if (!indexInfo->ii_Unique && !indexInfo->ii_ExclusionOps) {
+            continue;
+        }
+
+        Relation indexRelation = resultRelInfo->ri_IndexRelationDescs[i];
+        char* indexName = RelationGetRelationName(indexRelation);
+        idxNames = lappend(idxNames, indexName);
+    }
+
+    ExplainPropertyText("Conflict Resolution",
+                        mtstate->mt_upsert->us_action == UPSERT_NOTHING ? "NOTHING" : "UPDATE",
+                        es);
+    /*
+     * Don't display arbiter indexes at all when DO NOTHING variant
+     * implicitly ignores all conflicts
+     */
+    if (idxNames != NIL) {
+        ExplainPropertyList("Conflict Arbiter Indexes", idxNames, es);
+    }
+}
+
 #ifndef PGXC
 /*
  * Show extra information for a ModifyTable node
diff --git a/src/gausskernel/optimizer/commands/tablecmds.cpp b/src/gausskernel/optimizer/commands/tablecmds.cpp
index 4d3be9c3f..636166ffa 100644
--- a/src/gausskernel/optimizer/commands/tablecmds.cpp
+++ b/src/gausskernel/optimizer/commands/tablecmds.cpp
@@ -18804,7 +18804,7 @@ static void checkValidationForExchangeCStore(Relation partTableRel, Relation ord
         // init cstore partition insert
         resultRelInfo = makeNode(ResultRelInfo);
         InitResultRelInfo(resultRelInfo, partTableRel, 1, 0);
-        ExecOpenIndices(resultRelInfo);
+        ExecOpenIndices(resultRelInfo, false);
         resultRelInfo->ri_junkFilter = makeNode(JunkFilter);
         resultRelInfo->ri_junkFilter->jf_junkAttNo = tididx;
         resultRelInfo->ri_junkFilter->jf_xc_part_id = tableoidIdx;
diff --git a/src/gausskernel/optimizer/commands/trigger.cpp b/src/gausskernel/optimizer/commands/trigger.cpp
index 08c8c6e33..255c71be4 100644
--- a/src/gausskernel/optimizer/commands/trigger.cpp
+++ b/src/gausskernel/optimizer/commands/trigger.cpp
@@ -2616,6 +2616,11 @@ static HeapTuple GetTupleForTrigger(EState* estate, EPQState* epqstate, ResultRe
             LockTupleExclusive,
             false);
         switch (test) {
+            case HeapTupleSelfCreated:
+                ReleaseBuffer(buffer);
+                ereport(ERROR, (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
+                    errmsg("attempted to lock invisible tuple")));
+                break;
             case HeapTupleSelfUpdated:
                 /* treat it as deleted; do not process */
                 ReleaseBuffer(buffer);
diff --git a/src/gausskernel/optimizer/plan/createplan.cpp b/src/gausskernel/optimizer/plan/createplan.cpp
index 6c3171404..d2391db52 100644
--- a/src/gausskernel/optimizer/plan/createplan.cpp
+++ b/src/gausskernel/optimizer/plan/createplan.cpp
@@ -8298,11 +8298,11 @@ static void deparallelize_modifytable(List* subplans)
 #ifdef STREAMPLAN
 Plan* make_modifytable(PlannerInfo* root, CmdType operation, bool canSetTag, List* resultRelations, List* subplans,
     List* returningLists, List* rowMarks, int epqParam, bool partKeyUpdated, Index mergeTargetRelation,
-    List* mergeSourceTargetList, List* mergeActionList, bool isDfsStore)
+    List* mergeSourceTargetList, List* mergeActionList, UpsertExpr* upsertClause, bool isDfsStore)
 #else
 ModifyTable* make_modifytable(CmdType operation, bool canSetTag, List* resultRelations, List* subplans,
     List* returningLists, List* rowMarks, int epqParam, bool partKeyUpdated, Index mergeTargetRelation,
-    List* mergeSourceTargetList, List* mergeActionList, bool isDfsStore)
+    List* mergeSourceTargetList, List* mergeActionList, UpsertExpr* upsertClause, bool isDfsStore)
 #endif
 {
     ModifyTable* node = makeNode(ModifyTable);
@@ -8377,6 +8377,16 @@ ModifyTable* make_modifytable(CmdType operation, bool canSetTag, List* resultRel
     node->mergeTargetRelation = mergeTargetRelation;
     node->mergeSourceTargetList = mergeSourceTargetList;
     node->mergeActionList = mergeActionList;
+    if (upsertClause != NULL) {
+        node->upsertAction = upsertClause->upsertAction;
+        node->updateTlist = upsertClause->updateTlist;
+        node->exclRelTlist = upsertClause->exclRelTlist;
+        node->exclRelRTIndex = upsertClause->exclRelIndex;
+    } else {
+        node->upsertAction = UPSERT_NONE;
+        node->updateTlist = NIL;
+        node->exclRelTlist = NIL;
+    }
 
 #ifdef STREAMPLAN
     node->plan.exec_nodes = exec_nodes;
@@ -8507,11 +8517,11 @@ ModifyTable* make_modifytable(CmdType operation, bool canSetTag, List* resultRel
  */
 Plan* make_modifytables(PlannerInfo* root, CmdType operation, bool canSetTag, List* resultRelations, List* subplans,
     List* returningLists, List* rowMarks, int epqParam, bool partKeyUpdated, bool isDfsStore, Index mergeTargetRelation,
-    List* mergeSourceTargetList, List* mergeActionList)
+    List* mergeSourceTargetList, List* mergeActionList, UpsertExpr* upsertClause)
 #else
 ModifyTable* make_modifytables(CmdType operation, bool canSetTag, List* resultRelations, List* subplans,
     List* returningLists, List* rowMarks, int epqParam, bool partKeyUpdated, bool isDfsStore, Index mergeTargetRelation,
-    List* mergeSourceTargetList, List* mergeActionList)
+    List* mergeSourceTargetList, List* mergeActionList, UpsertExpr* upsertClause)
 #endif
 {
     if (isDfsStore) {
@@ -8542,6 +8552,7 @@ ModifyTable* make_modifytables(CmdType operation, bool canSetTag, List* resultRe
                 0,
                 NULL,
                 NULL,
+                upsertClause,
                 isDfsStore);
             /*
              * We must adjust the plan tree. Because the make_modifytable function would make a
@@ -8593,6 +8604,7 @@ ModifyTable* make_modifytables(CmdType operation, bool canSetTag, List* resultRe
                 0,
                 NULL,
                 NULL,
+                upsertClause,
                 isDfsStore);
             appendSubPlans = lappend(appendSubPlans, (void*)mtplan);
 #endif
@@ -8627,6 +8639,7 @@ ModifyTable* make_modifytables(CmdType operation, bool canSetTag, List* resultRe
             mergeTargetRelation,
             mergeSourceTargetList,
             mergeActionList,
+            upsertClause,
             isDfsStore);
         if (IS_STREAM_PLAN)
             return mt_stream_plan;
@@ -8644,6 +8657,7 @@ ModifyTable* make_modifytables(CmdType operation, bool canSetTag, List* resultRe
             mergeTargetRelation,
             mergeSourceTargetList,
             mergeActionList,
+            upsertClause
             isDfsStore);
         return pgxc_make_modifytable(root, (Plan*)mtplan);
 #endif
@@ -8659,6 +8673,7 @@ ModifyTable* make_modifytables(CmdType operation, bool canSetTag, List* resultRe
             mergeTargetRelation,
             mergeSourceTargetList,
             mergeActionList,
+            upsertClause,
             isDfsStore);
 #endif
     }
@@ -8952,7 +8967,7 @@ List* process_agg_targetlist(PlannerInfo* root, List** local_tlist)
          * We are about to change the local_tlist, check if we have already
          * copied original local_tlist, if not take a copy
          */
-        if ((orig_local_tlist == NULL) && (IsA(expr, Aggref) || context.aggs))
+        if ((orig_local_tlist == NIL) && (IsA(expr, Aggref) || context.aggs))
             orig_local_tlist = (List*)copyObject(*local_tlist);
 
         /*
diff --git a/src/gausskernel/optimizer/plan/planner.cpp b/src/gausskernel/optimizer/plan/planner.cpp
index 8f202bd76..415acf524 100644
--- a/src/gausskernel/optimizer/plan/planner.cpp
+++ b/src/gausskernel/optimizer/plan/planner.cpp
@@ -1332,6 +1332,10 @@ Plan* subquery_planner(PlannerGlobal* glob, Query* parse, PlannerInfo* parent_ro
     parse->mergeSourceTargetList =
         (List*)preprocess_expression(root, (Node*)parse->mergeSourceTargetList, EXPRKIND_TARGET);
 
+    if (parse->upsertClause) {
+        parse->upsertClause->updateTlist = (List*)
+            preprocess_expression(root, (Node*)parse->upsertClause->updateTlist, EXPRKIND_TARGET);
+    }
     root->append_rel_list = (List*)preprocess_expression(root, (Node*)root->append_rel_list, EXPRKIND_APPINFO);
 
     /* Also need to preprocess expressions for function and values RTEs */
@@ -1521,6 +1525,7 @@ Plan* subquery_planner(PlannerGlobal* glob, Query* parse, PlannerInfo* parent_ro
                 parse->mergeTarget_relation,
                 parse->mergeSourceTargetList,
                 parse->mergeActionList,
+                parse->upsertClause,
                 isDfsStore);
 #else
             plan = (Plan*)make_modifytable(parse->commandType,
@@ -1534,6 +1539,7 @@ Plan* subquery_planner(PlannerGlobal* glob, Query* parse, PlannerInfo* parent_ro
                 parse->mergeTarget_relation,
                 parse->mergeSourceTargetList,
                 parse->mergeActionList,
+                parse->upsertClause,
                 isDfsStore);
 #endif
 #ifdef PGXC
@@ -2014,6 +2020,7 @@ static Plan* inheritance_planner(PlannerInfo* root)
         isDfsStore,
         0,
         NULL,
+        NULL,
         NULL);
 #else
     return make_modifytables(parse->commandType,
@@ -2027,6 +2034,7 @@ static Plan* inheritance_planner(PlannerInfo* root)
         isDfsStore,
         0,
         NULL,
+        NULL,
         NULL);
 #endif
 }
@@ -2445,6 +2453,11 @@ static Plan* grouping_planner(PlannerInfo* root, double tuple_fraction)
         /* Preprocess targetlist */
         tlist = preprocess_targetlist(root, tlist);
 
+        if (parse->upsertClause) {
+            UpsertExpr* upsertClause = parse->upsertClause;
+            upsertClause->updateTlist =
+                preprocess_upsert_targetlist(upsertClause->updateTlist, parse->resultRelation, parse->rtable);
+        }
         /*
          * Locate any window functions in the tlist.  (We don't need to look
          * anywhere else, since expressions used in ORDER BY will be in there
diff --git a/src/gausskernel/optimizer/plan/setrefs.cpp b/src/gausskernel/optimizer/plan/setrefs.cpp
index d9b0c9645..a64541b86 100755
--- a/src/gausskernel/optimizer/plan/setrefs.cpp
+++ b/src/gausskernel/optimizer/plan/setrefs.cpp
@@ -830,6 +830,15 @@ static Plan* set_plan_refs(PlannerInfo* root, Plan* plan, int rtoffset)
                 }
             }
 
+            if (splan->updateTlist != NIL) {
+                indexed_tlist* itlist;
+                itlist = build_tlist_index(splan->exclRelTlist);
+                splan->updateTlist = fix_join_expr(root, splan->updateTlist, NULL,
+                    itlist, linitial_int(splan->resultRelations), rtoffset);
+            }
+
+            splan->exclRelRTIndex += rtoffset;
+
             foreach (l, splan->resultRelations) {
                 lfirst_int(l) += rtoffset;
             }
diff --git a/src/gausskernel/optimizer/plan/subselect.cpp b/src/gausskernel/optimizer/plan/subselect.cpp
index a021a792c..3ff05af07 100755
--- a/src/gausskernel/optimizer/plan/subselect.cpp
+++ b/src/gausskernel/optimizer/plan/subselect.cpp
@@ -2578,6 +2578,7 @@ static Bitmapset* finalize_plan(PlannerInfo* root, Plan* plan, Bitmapset* valid_
             valid_params = bms_add_member(bms_copy(valid_params), locally_added_param);
             scan_params = bms_add_member(bms_copy(scan_params), locally_added_param);
             (void)finalize_primnode((Node*)mtplan->returningLists, &context);
+            (void)finalize_primnode((Node*)mtplan->updateTlist, &context);
             finalize_plans(root, &context, mtplan->plans, valid_params, scan_params);
         } break;
 #ifdef PGXC
diff --git a/src/gausskernel/optimizer/prep/prepjointree.cpp b/src/gausskernel/optimizer/prep/prepjointree.cpp
index e3dd08871..835f8ddb8 100755
--- a/src/gausskernel/optimizer/prep/prepjointree.cpp
+++ b/src/gausskernel/optimizer/prep/prepjointree.cpp
@@ -1056,6 +1056,10 @@ static Node* pull_up_simple_subquery(PlannerInfo* root, Node* jtnode, RangeTblEn
      */
     parse->targetList = (List*)pullup_replace_vars((Node*)parse->targetList, &rvcontext);
     parse->returningList = (List*)pullup_replace_vars((Node*)parse->returningList, &rvcontext);
+    if (parse->upsertClause != NULL) {
+        parse->upsertClause->updateTlist = (List*)
+            pullup_replace_vars((Node*)parse->upsertClause->updateTlist, &rvcontext);
+    }
 
     replace_vars_in_jointree((Node*)parse->jointree, &rvcontext, lowest_outer_join);
 
diff --git a/src/gausskernel/optimizer/prep/preptlist.cpp b/src/gausskernel/optimizer/prep/preptlist.cpp
index b0b1de5a3..fa82ab05a 100644
--- a/src/gausskernel/optimizer/prep/preptlist.cpp
+++ b/src/gausskernel/optimizer/prep/preptlist.cpp
@@ -555,5 +555,10 @@ static List* add_distribute_column(List* tlist, Index result_relation, List* ran
 
     return tlist;
 }
+
+List* preprocess_upsert_targetlist(List* tlist, int result_relation, List* range_table)
+{
+    return expand_targetlist(tlist, CMD_UPDATE, result_relation, range_table);
+}
 #endif
 
diff --git a/src/gausskernel/optimizer/rewrite/rewriteHandler.cpp b/src/gausskernel/optimizer/rewrite/rewriteHandler.cpp
index a6a345704..3d6ea7bf1 100644
--- a/src/gausskernel/optimizer/rewrite/rewriteHandler.cpp
+++ b/src/gausskernel/optimizer/rewrite/rewriteHandler.cpp
@@ -57,7 +57,8 @@ static bool acquireLocksOnSubLinks(Node* node, void* context);
 static Query* rewriteRuleAction(
     Query* parsetree, Query* rule_action, Node* rule_qual, int rt_index, CmdType event, bool* returning_flag);
 static List* adjustJoinTreeList(Query* parsetree, bool removert, int rt_index);
-static void rewriteTargetListIU(Query* parsetree, Relation target_relation, List** attrno_list);
+static List* rewriteTargetListIU(List* targetList, CmdType commandType,
+    Relation target_relation, int result_rtindex, List** attrno_list);
 static TargetEntry* process_matched_tle(TargetEntry* src_tle, TargetEntry* prior_tle, const char* attrName);
 static Node* get_assignment_input(Node* node);
 static void rewriteValuesRTE(RangeTblEntry* rte, Relation target_relation, List* attrnos);
@@ -613,9 +614,9 @@ static List* adjustJoinTreeList(Query* parsetree, bool removert, int rt_index)
  * order of the original tlist's non-junk entries.  This is needed for
  * processing VALUES RTEs.
  */
-static void rewriteTargetListIU(Query* parsetree, Relation target_relation, List** attrno_list)
+static List* rewriteTargetListIU(List* targetList, CmdType commandType, Relation target_relation,
+    int result_rtindex, List** attrno_list)
 {
-    CmdType commandType = parsetree->commandType;
     TargetEntry** new_tles;
     List* new_tlist = NIL;
     List* junk_tlist = NIL;
@@ -639,7 +640,7 @@ static void rewriteTargetListIU(Query* parsetree, Relation target_relation, List
     new_tles = (TargetEntry**)palloc0(numattrs * sizeof(TargetEntry*));
     next_junk_attrno = numattrs + 1;
 
-    foreach (temp, parsetree->targetList) {
+    foreach (temp, targetList) {
         TargetEntry* old_tle = (TargetEntry*)lfirst(temp);
 
         if (!old_tle->resjunk) {
@@ -737,8 +738,7 @@ static void rewriteTargetListIU(Query* parsetree, Relation target_relation, List
             Node* new_expr = NULL;
 
             new_expr = (Node*)makeVar(
-                (unsigned int)(parsetree->resultRelation), attrno, att_tup->atttypid, att_tup->atttypmod,
-                att_tup->attcollation, 0);
+                result_rtindex, attrno, att_tup->atttypid, att_tup->atttypmod, att_tup->attcollation, 0);
 
             new_tle = makeTargetEntry((Expr*)new_expr, (int16)attrno, pstrdup(NameStr(att_tup->attname)), false);
         }
@@ -748,8 +748,8 @@ static void rewriteTargetListIU(Query* parsetree, Relation target_relation, List
     }
 
     pfree_ext(new_tles);
-
-    parsetree->targetList = list_concat(new_tlist, junk_tlist);
+    targetList = list_concat(new_tlist, junk_tlist);
+    return targetList;
 }
 
 /*
@@ -2303,15 +2303,28 @@ static List* RewriteQuery(Query* parsetree, List* rewrite_events)
                 List* attrnos = NIL;
 
                 /* Process the main targetlist ... */
-                rewriteTargetListIU(parsetree, rt_entry_relation, &attrnos);
+                parsetree->targetList =
+                    rewriteTargetListIU(parsetree->targetList, parsetree->commandType,
+                                        rt_entry_relation, parsetree->resultRelation, &attrnos);
                 /* ... and the VALUES expression lists */
                 rewriteValuesRTE(values_rte, rt_entry_relation, attrnos);
             } else {
                 /* Process just the main targetlist */
-                rewriteTargetListIU(parsetree, rt_entry_relation, NULL);
+                parsetree->targetList =
+                    rewriteTargetListIU(parsetree->targetList, parsetree->commandType,
+                                        rt_entry_relation, parsetree->resultRelation, NULL);
+            }
+
+            if (parsetree->upsertClause != NULL &&
+                parsetree->upsertClause->upsertAction == UPSERT_UPDATE) {
+                parsetree->upsertClause->updateTlist =
+                    rewriteTargetListIU(parsetree->upsertClause->updateTlist, CMD_UPDATE,
+                                        rt_entry_relation, parsetree->resultRelation, NULL);
             }
         } else if (event == CMD_UPDATE) {
-            rewriteTargetListIU(parsetree, rt_entry_relation, NULL);
+            parsetree->targetList =
+                rewriteTargetListIU(parsetree->targetList, parsetree->commandType,
+                                    rt_entry_relation, parsetree->resultRelation, NULL);
             rewriteTargetListUD(parsetree, rt_entry, rt_entry_relation);
         } else if (event == CMD_MERGE) {
             /*
diff --git a/src/gausskernel/runtime/executor/execMain.cpp b/src/gausskernel/runtime/executor/execMain.cpp
index bce75c951..d9d527ad4 100644
--- a/src/gausskernel/runtime/executor/execMain.cpp
+++ b/src/gausskernel/runtime/executor/execMain.cpp
@@ -2762,6 +2762,11 @@ HeapTuple EvalPlanQualFetch(EState *estate, Relation relation, int lockmode, Ite
             ReleaseBuffer(buffer);
 
             switch (test) {
+                case HeapTupleSelfCreated:
+                    ReleaseBuffer(buffer);
+                    ereport(ERROR, (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
+                        errmsg("attempted to lock invisible tuple")));
+                    break;
                 case HeapTupleSelfUpdated:
                     /* treat it as deleted; do not process */
                     ReleaseBuffer(buffer);
diff --git a/src/gausskernel/runtime/executor/execUtils.cpp b/src/gausskernel/runtime/executor/execUtils.cpp
index 30dad3e92..c624cfc35 100755
--- a/src/gausskernel/runtime/executor/execUtils.cpp
+++ b/src/gausskernel/runtime/executor/execUtils.cpp
@@ -64,6 +64,8 @@ static bool get_last_attnums(Node* node, ProjectionInfo* projInfo);
 static bool index_recheck_constraint(
     Relation index, Oid* constr_procs, Datum* existing_values, const bool* existing_isnull, Datum* new_values);
 static void ShutdownExprContext(ExprContext* econtext, bool isCommit);
+static bool check_violation(Relation heap, Relation index, IndexInfo *indexInfo, ItemPointer tupleid, Datum *values,
+    const bool *isnull, EState *estate, bool newIndex, bool errorOK, CheckWaitMode waitMode, ItemPointer conflictTid);
 
 /* ----------------------------------------------------------------
  *				 Executor state and memory management functions
@@ -1100,7 +1102,7 @@ Partition ExecOpenScanParitition(EState* estate, Relation parent, PartitionIdent
  *		resultRelInfo->ri_RelationDesc.
  * ----------------------------------------------------------------
  */
-void ExecOpenIndices(ResultRelInfo* resultRelInfo)
+void ExecOpenIndices(ResultRelInfo* resultRelInfo, bool speculative)
 {
     Relation resultRelation = resultRelInfo->ri_RelationDesc;
     List* indexoidlist = NIL;
@@ -1156,6 +1158,13 @@ void ExecOpenIndices(ResultRelInfo* resultRelInfo)
         /* extract index key information from the index's pg_index info */
         ii = BuildIndexInfo(indexDesc);
 
+        /*
+         * If the indexes are to be used for speculative insertion, add extra
+         * information required by unique index entries.
+         */
+        if (speculative && ii->ii_Unique) {
+            BuildSpeculativeIndexInfo(indexDesc, ii);
+        }
         relationDescs[i] = indexDesc;
         indexInfoArray[i] = ii;
         i++;
@@ -1195,6 +1204,164 @@ void ExecCloseIndices(ResultRelInfo* resultRelInfo)
      */
 }
 
+/* ----------------------------------------------------------------
+ *     ExecCheckIndexConstraints
+ *
+ *     This routine checks if a tuple violates any unique or
+ *     exclusion constraints.  Returns true if there is no no conflict.
+ *     Otherwise returns false, and the TID of the conflicting
+ *     tuple is returned in *conflictTid.
+ *
+ *     Note that this doesn't lock the values in any way, so it's
+ *     possible that a conflicting tuple is inserted immediately
+ *     after this returns.  But this can be used for a pre-check
+ *     before insertion.
+ * ----------------------------------------------------------------
+ */
+bool ExecCheckIndexConstraints(TupleTableSlot* slot, EState* estate,
+    Relation targetRel, Partition p, int2 bucketId, ItemPointer conflictTid)
+{
+    ResultRelInfo* resultRelInfo = NULL;
+    RelationPtr relationDescs = NULL;
+    int i = 0;
+    int 	numIndices = 0;
+    IndexInfo** indexInfoArray = NULL;
+    Relation heapRelationDesc = NULL;
+    Relation actualHeap = NULL;
+    ExprContext* econtext = NULL;
+    Datum values[INDEX_MAX_KEYS];
+    bool isnull[INDEX_MAX_KEYS];
+    ItemPointerData invalidItemPtr;
+    bool isPartitioned = false;
+    List* partitionIndexOidList = NIL;
+
+    ItemPointerSetInvalid(conflictTid);
+    ItemPointerSetInvalid(&invalidItemPtr);
+
+    /*
+     * Get information from the result relation info structure.
+     */
+    resultRelInfo = estate->es_result_relation_info;
+    numIndices = resultRelInfo->ri_NumIndices;
+    relationDescs = resultRelInfo->ri_IndexRelationDescs;
+    indexInfoArray = resultRelInfo->ri_IndexRelationInfo;
+    heapRelationDesc = resultRelInfo->ri_RelationDesc;
+    actualHeap = targetRel;
+
+    if (RELATION_IS_PARTITIONED(heapRelationDesc)) {
+        Assert(p != NULL && p->pd_part != NULL);
+        isPartitioned = true;
+
+        if (!p->pd_part->indisusable) {
+            return false;
+        }
+    }
+
+    /*
+     * use the EState's per-tuple context for evaluating predicates
+     * and index expressions (creating it if it's not already there).
+     */
+    econtext = GetPerTupleExprContext(estate);
+
+    /* Arrange for econtext's scan tuple to be the tuple under test */
+    econtext->ecxt_scantuple = slot;
+
+    /*
+     * For each index, form index tuple and check if it satisfies the
+     * constraint.
+     */
+    for (i = 0; i < numIndices; i++) {
+        Relation indexRelation = relationDescs[i];
+        IndexInfo* indexInfo;
+        bool satisfiesConstraint;
+        Relation actualIndex = NULL;
+        Oid partitionedindexid = InvalidOid;
+        Oid indexpartitionid = InvalidOid;
+        Partition indexpartition = NULL;
+
+        if (indexRelation == NULL)
+            continue;
+
+        indexInfo = indexInfoArray[i];
+
+        if (!indexInfo->ii_Unique && !indexInfo->ii_ExclusionOps)
+            continue;
+
+        /* If the index is marked as read-only, ignore it */
+        if (!indexInfo->ii_ReadyForInserts)
+            continue;
+
+        if (!indexRelation->rd_index->indimmediate)
+            ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+                             errmsg("INSERT ON DUPLICATE KEY UPDATE does not support deferrable"
+                                    " unique constraints/exclusion constraints.")));
+        if (isPartitioned) {
+            partitionedindexid = RelationGetRelid(indexRelation);
+            if (!PointerIsValid(partitionIndexOidList)) {
+                partitionIndexOidList = PartitionGetPartIndexList(p);
+                if (!PointerIsValid(partitionIndexOidList)) {
+                    // no local indexes available
+                    return false;
+                }
+            }
+
+            indexpartitionid = searchPartitionIndexOid(partitionedindexid, partitionIndexOidList);
+
+            searchFakeReationForPartitionOid(estate->esfRelations,
+                estate->es_query_cxt,
+                indexRelation,
+                indexpartitionid,
+                actualIndex,
+                indexpartition,
+                RowExclusiveLock);
+            /* skip unusable index */
+            if (indexpartition->pd_part->indisusable == false) {
+                continue;
+            }
+        } else {
+            actualIndex = indexRelation;
+        }
+
+        if (bucketId != InvalidBktId) {
+            searchHBucketFakeRelation(estate->esfRelations, estate->es_query_cxt, actualIndex, bucketId, actualIndex);
+        }
+
+        /* Check for partial index */
+        if (indexInfo->ii_Predicate != NIL) {
+            List* predicate;
+
+            /*
+             * If predicate state not set up yet, create it (in the estate's
+             * per-query context)
+             */
+            predicate = indexInfo->ii_PredicateState;
+            if (predicate == NIL) {
+                predicate = (List*)ExecPrepareExpr((Expr*)indexInfo->ii_Predicate, estate);
+                indexInfo->ii_PredicateState = predicate;
+            }
+
+            /* Skip this index-update if the predicate isn't satisfied */
+            if (!ExecQual(predicate, econtext, false)) {
+                continue;
+            }
+        }
+
+        /*
+        * FormIndexDatum fills in its values and isnull parameters with the
+        * appropriate values for the column(s) of the index.
+        */
+        FormIndexDatum(indexInfo, slot, estate, values, isnull);
+
+        satisfiesConstraint = check_violation(actualHeap, actualIndex, indexInfo, &invalidItemPtr, values, isnull,
+            estate, false, true, CHECK_WAIT, conflictTid);
+        if (!satisfiesConstraint) {
+            return false;
+        }
+    }
+
+    return true;
+}
+
 /* ----------------------------------------------------------------
  *		ExecInsertIndexTuples
  *
@@ -1215,8 +1382,8 @@ void ExecCloseIndices(ResultRelInfo* resultRelInfo)
  *		Should we change the API to make it safer?
  * ----------------------------------------------------------------
  */
-List* ExecInsertIndexTuples(
-    TupleTableSlot* slot, ItemPointer tupleid, EState* estate, Relation targetPartRel, Partition p, int2 bucketId)
+List* ExecInsertIndexTuples(TupleTableSlot* slot, ItemPointer tupleid, EState* estate,
+    Relation targetPartRel, Partition p, int2 bucketId, bool* conflict)
 {
     List* result = NIL;
     ResultRelInfo* resultRelInfo = NULL;
@@ -1362,6 +1529,8 @@ List* ExecInsertIndexTuples(
          */
         if (!indexRelation->rd_index->indisunique) {
             checkUnique = UNIQUE_CHECK_NO;
+        } else if (conflict != NULL) {
+            checkUnique = UNIQUE_CHECK_PARTIAL;
         } else if (indexRelation->rd_index->indimmediate) {
             checkUnique = UNIQUE_CHECK_YES;
         } else {
@@ -1397,9 +1566,13 @@ List* ExecInsertIndexTuples(
             /*
              * The tuple potentially violates the uniqueness or exclusion
              * constraint, so make a note of the index so that we can re-check
-             * it later.
+             * it later. Speculative inserters are told if there was a
+             * speculative conflict, since that always requires a restart.
              */
             result = lappend_oid(result, RelationGetRelid(indexRelation));
+            if (conflict != NULL) {
+                *conflict = true;
+            }
         }
     }
 
@@ -1433,6 +1606,13 @@ List* ExecInsertIndexTuples(
  */
 bool check_exclusion_constraint(Relation heap, Relation index, IndexInfo* indexInfo, ItemPointer tupleid, Datum* values,
     const bool* isnull, EState* estate, bool newIndex, bool errorOK)
+{
+    return check_violation(heap, index, indexInfo, tupleid, values, isnull,
+        estate, newIndex, errorOK, errorOK ? CHECK_NOWAIT : CHECK_WAIT, NULL);
+}
+
+bool check_violation(Relation heap, Relation index, IndexInfo* indexInfo, ItemPointer tupleid, Datum* values,
+    const bool* isnull, EState* estate, bool newIndex, bool errorOK, CheckWaitMode waitMode, ItemPointer conflictTid)
 {
     Oid* constr_procs = indexInfo->ii_ExclusionProcs;
     uint16* constr_strats = indexInfo->ii_ExclusionStrats;
@@ -1459,6 +1639,13 @@ bool check_exclusion_constraint(Relation heap, Relation index, IndexInfo* indexI
         }
     }
 
+    if (indexInfo->ii_ExclusionOps) {
+        constr_procs = indexInfo->ii_ExclusionProcs;
+        constr_strats = indexInfo->ii_ExclusionStrats;
+    } else {
+        constr_procs = indexInfo->ii_UniqueProcs;
+        constr_strats = indexInfo->ii_UniqueStrats;
+    }
     /*
      * Search the tuples that are in the index for any violations, including
      * tuples that aren't visible yet.
@@ -1503,7 +1690,7 @@ retry:
         /*
          * Ignore the entry for the tuple we're trying to check.
          */
-        if (ItemPointerEquals(tupleid, &tup->t_self)) {
+        if (ItemPointerIsValid(tupleid) && ItemPointerEquals(tupleid, &tup->t_self)) {
             if (found_self) /* should not happen */
                 ereport(ERROR,
                     (errcode(ERRCODE_FETCH_DATA_FAILED),
@@ -1527,33 +1714,44 @@ retry:
         }
 
         /*
-         * At this point we have either a conflict or a potential conflict. If
-         * we're not supposed to raise error, just return the fact of the
-         * potential conflict without waiting to see if it's real.
-         */
-        if (errorOK) {
-            conflict = true;
-            break;
-        }
-
-        /*
+         * At this point we have either a conflict or a potential conflict.
          * If an in-progress transaction is affecting the visibility of this
-         * tuple, we need to wait for it to complete and then recheck.	For
-         * simplicity we do rechecking by just restarting the whole scan ---
-         * this case probably doesn't happen often enough to be worth trying
-         * harder, and anyway we don't want to hold any index internal locks
-         * while waiting.
+         * tuple, we need to wait for it to complete and then recheck (unless
+         * the caller requested not to).  For simplicity we do rechecking by
+         * just restarting the whole scan --- this case probably doesn't
+         * happen often enough to be worth trying harder, and anyway we don't
+         * want to hold any index internal locks while waiting.
          */
         xwait = TransactionIdIsValid(DirtySnapshot.xmin) ? DirtySnapshot.xmin : DirtySnapshot.xmax;
 
-        if (TransactionIdIsValid(xwait)) {
+        if (TransactionIdIsValid(xwait) && waitMode == CHECK_WAIT) {
             index_endscan(index_scan);
+
+            /* for speculative insertion (INSERT ON DUPLICATE KEY UPDATE),
+             * we only need to wait the speculative token lock to be release,
+             * which happens when the tuple is speculative inserted by other
+             * running transction, and has done it's insertion (eithter
+             * finished or aborted).
+             */
             XactLockTableWait(xwait);
             goto retry;
         }
 
         /*
-         * We have a definite conflict.  Report it.
+         * We have a definite conflict (or a potential one, but the caller
+         * didn't want to wait). If we're not supposed to raise error, just
+         * return to the caller.
+         */
+        if (errorOK) {
+            conflict = true;
+            if (conflictTid != NULL)
+                *conflictTid = tup->t_self;
+            break;
+        }
+
+        /*
+         * We have a definite conflict (or a potential one, but the caller
+         * didn't want to wait).  Report it.
          */
         error_new = BuildIndexValueDescription(index, values, isnull);
         error_existing = BuildIndexValueDescription(index, existing_values, existing_isnull);
@@ -1578,7 +1776,7 @@ retry:
 
     /*
      * Ordinarily, at this point the search should have found the originally
-     * inserted tuple, unless we exited the loop early because of conflict.
+     * inserted tuple (if any), unless we exited the loop early because of conflict.
      * However, it is possible to define exclusion constraints for which that
      * wouldn't be true --- for instance, if the operator is <>. So we no
      * longer complain if found_self is still false.
diff --git a/src/gausskernel/runtime/executor/nodeLockRows.cpp b/src/gausskernel/runtime/executor/nodeLockRows.cpp
index cde8d6a48..e702ea46a 100755
--- a/src/gausskernel/runtime/executor/nodeLockRows.cpp
+++ b/src/gausskernel/runtime/executor/nodeLockRows.cpp
@@ -184,6 +184,10 @@ lnext:
             bucket_rel, &tuple, &buffer, &update_ctid, &update_xmax, estate->es_output_cid, lock_mode, erm->noWait);
         ReleaseBuffer(buffer);
         switch (test) {
+            case HeapTupleSelfCreated:
+                ereport(ERROR, (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
+                    errmsg("attempted to lock invisible tuple")));
+                break;
             case HeapTupleSelfUpdated:
                 /* treat it as deleted; do not process */
                 goto lnext;
diff --git a/src/gausskernel/runtime/executor/nodeModifyTable.cpp b/src/gausskernel/runtime/executor/nodeModifyTable.cpp
index d40c94d5b..cdcbb5a44 100644
--- a/src/gausskernel/runtime/executor/nodeModifyTable.cpp
+++ b/src/gausskernel/runtime/executor/nodeModifyTable.cpp
@@ -248,6 +248,277 @@ static TupleTableSlot* ExecProcessReturning(
     return ExecProject(projectReturning, NULL);
 }
 
+static void ExecCheckHeapTupleVisible(EState* estate, HeapTuple tuple, Buffer buffer)
+{
+    if (!IsolationUsesXactSnapshot())
+        return;
+
+    if (!HeapTupleSatisfiesVisibility(tuple, estate->es_snapshot, buffer))
+        ereport(ERROR,
+                (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
+                 errmsg("could not serialize access due to concurrent update")));
+}
+
+static void ExecCheckTIDVisible(EState* estate, Relation rel, ItemPointer tid)
+{
+    Buffer      buffer;
+    HeapTupleData tuple;
+
+    /* check isolation level to tell if tuple visibility check is needed */
+    if (!IsolationUsesXactSnapshot()) {
+        return;
+    }
+
+    tuple.t_self = *tid;
+    if (!heap_fetch(rel, SnapshotAny, &tuple, &buffer, false, NULL)) {
+        ereport(ERROR, (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
+            errmsg("failed to fetch conflicting tuple for DUPLICATE KEY UPDATE")));
+    }
+
+    ExecCheckHeapTupleVisible(estate, &tuple, buffer);
+    ReleaseBuffer(buffer);
+}
+
+static bool ExecConflictUpdate(ModifyTableState* mtstate, ResultRelInfo* resultRelInfo, ItemPointer conflictTid,
+    TupleTableSlot* planSlot, TupleTableSlot* excludedSlot, EState* estate, Relation targetRel,
+    Oid oldPartitionOid, int2 bucketid, bool canSetTag, TupleTableSlot** returning)
+{
+    ExprContext* econtext = mtstate->ps.ps_ExprContext;
+    Relation    relation = targetRel;
+    UpsertState* upsertState = mtstate->mt_upsert;
+    HeapTupleData tuple;
+    HTSU_Result test;
+    Buffer      buffer;
+    ItemPointerData update_ctid;
+    TransactionId update_xmax;
+
+    tuple.t_self = *conflictTid;
+    test = heap_lock_tuple(relation, &tuple, &buffer,
+                           &update_ctid, &update_xmax,
+                           estate->es_output_cid, LockTupleExclusive, false);
+checktest:
+    switch (test) {
+        case HeapTupleMayBeUpdated:
+            /* success */
+            break;
+        case HeapTupleSelfCreated:
+            /*
+             * This can occur when a just inserted tuple is updated again in
+             * the same command. E.g. because multiple rows with the same
+             * conflicting key values are inserted using STREAM:
+             * INSERT INTO t VALUES(1),(1) ON DUPLICATE KEY UPDATE ...
+             *
+             * This is somewhat similar to the ExecUpdate()
+             * HeapTupleSelfUpdated case.  We do not want to proceed because
+             * it would lead to the same row being updated a second time in
+             * some unspecified order, and in contrast to plain UPDATEs
+             * there's no historical behavior to break.
+             *
+             * It is the user's responsibility to prevent this situation from
+             * occurring.  These problems are why SQL-2003 similarly specifies
+             * that for SQL MERGE, an exception must be raised in the event of
+             * an attempt to update the same row twice.
+             *
+             * However, in order by be compatible with SQL, we have to break the
+             * rule and update the same row which is created within the command.
+             */
+            ReleaseBuffer(buffer);
+#ifdef ENABLE_MULTIPLE_NODES
+            if (!(u_sess->attr.attr_sql.sql_compatibility & DB_CMPT_C)) {
+               ereport(ERROR, (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
+                   errmsg("ON DUPLICATE KEY UPDATE command cannot affect row a second time"),
+                   errhint("Ensure that no rows proposed for insertion within"
+                       "the same command have duplicate constrained values.")));
+            }
+#endif
+            test = heap_lock_tuple(relation, &tuple, &buffer, &update_ctid, &update_xmax,
+                                   estate->es_output_cid, LockTupleExclusive, false, true);
+            Assert(test != HeapTupleSelfCreated);
+            goto checktest;
+            break;
+        case HeapTupleSelfUpdated:
+            ReleaseBuffer(buffer);
+            /*
+             * This state should never be reached. As a dirty snapshot is used
+             * to find conflicting tuples, speculative insertion wouldn't have
+             * seen this row to conflict with.
+             */
+            ereport(ERROR, (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
+                errmsg("unexpected self-updated tuple")));
+            break;
+        case HeapTupleUpdated:
+            ReleaseBuffer(buffer);
+            if (IsolationUsesXactSnapshot()) {
+                ereport(ERROR, (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
+                    errmsg("could not serialize access due to concurrent update")));
+            }
+            /*
+             * Tell caller to try again from the very start.
+             * It does not make sense to use the usual EvalPlanQual() style
+             * loop here, as the new version of the row might not conflict
+             * anymore, or the conflicting tuple has actually been deleted.
+             */
+            return false;
+        case HeapTupleBeingUpdated:
+            ReleaseBuffer(buffer);
+            ereport(ERROR, (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
+                    errmsg("unexpected concurrent update tuple")));
+            break;
+        default:
+            ReleaseBuffer(buffer);
+            elog(ERROR, "unrecognized heap_lock_tuple status: %u", test);
+            break;
+    }
+
+    /*
+     * Success, the tuple is locked.
+     *
+     * Reset per-tuple memory context to free any expression evaluation
+     * storage allocated in the previous cycle.
+     */
+    ResetExprContext(econtext);
+
+    /* NOTE: we rely on ExecUpdate() to do MVCC snapshot check, thus projection is
+     * done here although the final ExecUpdate might be failed.
+     */
+    ExecCheckHeapTupleVisible(estate, &tuple, buffer);
+
+    /* Store target's existing tuple in the state's dedicated slot */
+    ExecStoreTuple(&tuple, upsertState->us_existing, buffer, false);
+
+    /*
+     * Make tuple and any needed join variables available to ExecQual and
+     * ExecProject.  The EXCLUDED tuple is installed in ecxt_innertuple, while
+     * the target's existing tuple is installed in the scantuple.  EXCLUDED has
+     * been made to reference INNER_VAR in setrefs.c, but there is no other redirection.
+     */
+    econtext->ecxt_scantuple = upsertState->us_existing;
+    econtext->ecxt_innertuple = excludedSlot;
+    econtext->ecxt_outertuple = NULL;
+
+    ExecProject(resultRelInfo->ri_updateProj, NULL);
+
+    *returning = ExecUpdate(conflictTid, oldPartitionOid, bucketid, NULL,
+                            upsertState->us_updateproj, planSlot, &mtstate->mt_epqstate,
+                            mtstate, canSetTag, false);
+    ReleaseBuffer(buffer);
+    return true;
+}
+
+
+static Oid ExecUpsert(ModifyTableState* state, TupleTableSlot* slot, TupleTableSlot* planSlot, EState* estate,
+    bool canSetTag, HeapTuple tuple, TupleTableSlot** returning, bool* updated)
+{
+    Oid newid = InvalidOid;
+    bool        specConflict;
+    List* recheckIndexes = NIL;
+    ResultRelInfo* resultRelInfo = NULL;
+    Relation    resultRelationDesc = NULL;
+    Relation    heaprel = NULL; /* actual relation to upsert index */
+    Relation    targetrel = NULL; /* actual relation to upsert tuple */
+    Oid         partitionid = InvalidOid; /* bucket id for bucket hash table */
+    Partition   partition = NULL; /* partition info for partition table */
+    int2 bucketid = InvalidBktId;
+    ItemPointerData conflictTid;
+    UpsertState* upsertState = state->mt_upsert;
+    *updated = false;
+
+    /*
+     * get information on the (current) result relation
+     */
+    resultRelInfo = estate->es_result_relation_info;
+    resultRelationDesc = resultRelInfo->ri_RelationDesc;
+    heaprel = resultRelationDesc;
+
+    if (unlikely(RelationIsCUFormat(resultRelationDesc))) {
+        ereport(ERROR,
+            (errmodule(MOD_EXECUTOR),
+            (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+            errmsg("ON DUPLICATE KEY UPDATE is not supported on column orientated table"))));
+    }
+
+    if (unlikely(RelationIsPAXFormat(resultRelationDesc))) {
+        ereport(ERROR,
+            (errmodule(MOD_EXECUTOR),
+             (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+              errmsg("ON DUPLICATE KEY UPDATE is not supported on DFS table"))));
+    }
+
+    if (RelationIsPartitioned(resultRelationDesc)) {
+        partitionid = heapTupleGetPartitionId(resultRelationDesc, tuple);
+        searchFakeReationForPartitionOid(estate->esfRelations,
+            estate->es_query_cxt,
+            resultRelationDesc,
+            partitionid,
+            heaprel,
+            partition,
+            RowExclusiveLock);
+    }
+
+    targetrel = heaprel;
+    if (RELATION_OWN_BUCKET(resultRelationDesc)) {
+        bucketid = computeTupleBucketId(resultRelationDesc, tuple);
+        if (unlikely(bucketid != InvalidBktId)) {
+            searchHBucketFakeRelation(estate->esfRelations, estate->es_query_cxt, heaprel, bucketid, targetrel);
+        }
+    }
+
+
+    vlock:
+    specConflict = false;
+    if (!ExecCheckIndexConstraints(slot, estate, targetrel, partition, bucketid, &conflictTid)) {
+        /* committed conflict tuple found */
+        if (upsertState->us_action == UPSERT_UPDATE) {
+            /*
+             * In case of DUPLICATE KEY UPDATE, execute the UPDATE part.
+             * Be prepared to retry if the UPDATE fails because
+             * of another concurrent UPDATE/DELETE to the conflict tuple.
+             */
+            *returning = NULL;
+
+            if (ExecConflictUpdate(state, resultRelInfo, &conflictTid, planSlot, slot, estate, targetrel, partitionid,
+                                   bucketid, canSetTag, returning)) {
+                InstrCountFiltered2(&state->ps, 1);
+                *updated = true;
+                return InvalidOid;
+            } else {
+                goto vlock;
+            }
+        } else {
+            /*
+             * In case of DUPLICATE UPDATE NOTHING, do nothing.
+             * However, verify that the tuple is visible to the
+             * executor's MVCC snapshot at higher isolation levels.
+             */
+            Assert(upsertState->us_action == UPSERT_NOTHING);
+            ExecCheckTIDVisible(estate, targetrel, &conflictTid);
+            InstrCountFiltered2(&state->ps, 1);
+            *updated = true;
+            return InvalidOid;
+        }
+    }
+
+    /* insert the tuple */
+    newid = heap_insert(targetrel, tuple, estate->es_output_cid, 0, NULL);
+
+    /* insert index entries for tuple */
+    recheckIndexes = ExecInsertIndexTuples(slot, &(tuple->t_self), estate, heaprel,
+        partition, bucketid, &specConflict);
+
+    /* other transaction commit index insertion before us,
+     * then abort the tuple and try to find the conflict tuple again
+     */
+    if (specConflict) {
+        heap_abort_speculative(targetrel, tuple);
+
+        list_free(recheckIndexes);
+        goto vlock;
+    }
+
+    return newid;
+}
+
+
 /* ----------------------------------------------------------------
  *		ExecInsert
  *
@@ -307,9 +578,12 @@ TupleTableSlot* ExecInsertT(ModifyTableState* state, TupleTableSlot* slot, Tuple
     if (result_relation_desc->rd_rel->relhasoids)
         HeapTupleSetOid(tuple, InvalidOid);
 
-    /* BEFORE ROW INSERT Triggers */
-    if (state->operation != CMD_MERGE && result_rel_info->ri_TrigDesc &&
-        result_rel_info->ri_TrigDesc->trig_insert_before_row) {
+    /* BEFORE ROW INSERT Triggers
+     * Note: We fire BEFORE ROW TRIGGERS for every attempted insertion in an except
+     * for a MERGE or INSERT ... ON DUPLICATE KEY UPDATE statement.
+     */
+    if (state->operation != CMD_MERGE &&
+        result_rel_info->ri_TrigDesc && result_rel_info->ri_TrigDesc->trig_insert_before_row) {
         slot = ExecBRInsertTriggers(estate, result_rel_info, slot);
         if (slot == NULL) /* "do nothing" */
             return NULL;
@@ -318,9 +592,12 @@ TupleTableSlot* ExecInsertT(ModifyTableState* state, TupleTableSlot* slot, Tuple
         tuple = ExecMaterializeSlot(slot);
     }
 
-    /* INSTEAD OF ROW INSERT Triggers */
-    if (state->operation != CMD_MERGE && result_rel_info->ri_TrigDesc &&
-        result_rel_info->ri_TrigDesc->trig_insert_instead_row) {
+    /* INSTEAD OF ROW INSERT Triggers 
+     * Note: We fire INSREAD OF ROW TRIGGERS for every attempted insertion except
+     * for a MERGE or INSERT ... ON DUPLICATE KEY UPDATE statement.
+     */
+    if (state->operation != CMD_MERGE &&
+        result_rel_info->ri_TrigDesc && result_rel_info->ri_TrigDesc->trig_insert_instead_row) {
         slot = ExecIRInsertTriggers(estate, result_rel_info, slot);
         if (slot == NULL) /* "do nothing" */
             return NULL;
@@ -449,6 +726,14 @@ TupleTableSlot* ExecInsertT(ModifyTableState* state, TupleTableSlot* slot, Tuple
                 }
 
                 ExecDropSingleTupleTableSlot(tmp_slot);
+            } else if (state->mt_upsert->us_action != UPSERT_NONE && result_rel_info->ri_NumIndices > 0) {
+                TupleTableSlot* returning = NULL;
+                bool updated = false;
+                new_id = InvalidOid;
+                new_id = ExecUpsert(state, slot, planSlot, estate, canSetTag, tuple, &returning, &updated);
+                if (updated) {
+                    return returning;
+                }
             } else {
                 /*
                  * insert the tuple
@@ -524,7 +809,7 @@ TupleTableSlot* ExecInsertT(ModifyTableState* state, TupleTableSlot* slot, Tuple
                         estate,
                         RELATION_IS_PARTITIONED(result_relation_desc) ? heap_rel : NULL,
                         RELATION_IS_PARTITIONED(result_relation_desc) ? partition : NULL,
-                        bucket_id);
+                        bucket_id, NULL);
             }
     }
 
@@ -539,7 +824,10 @@ TupleTableSlot* ExecInsertT(ModifyTableState* state, TupleTableSlot* slot, Tuple
         setLastTid(&(tuple->t_self));
     }
 
-    /* AFTER ROW INSERT Triggers */
+    /* AFTER ROW INSERT Triggers
+     * Note: We fire AFTER ROW TRIGGERS for every attempted insertion except
+     * for a MERGE or INSERT ... ON DUPLICATE KEY UPDATE statement.
+     */
     if (state->operation != CMD_MERGE && !useHeapMultiInsert)
         ExecARInsertTriggers(estate, result_rel_info, partition_id, bucket_id, tuple, recheck_indexes);
 
@@ -938,6 +1226,8 @@ TupleTableSlot* ExecUpdate(ItemPointer tupleid,
 #ifdef PGXC
     RemoteQueryState* result_remote_rel = NULL;
 #endif
+    bool allow_update_self = (node->mt_upsert != NULL &&
+        node->mt_upsert->us_action != UPSERT_NONE) ? true : false;
 
     /*
      * abort the operation if not running transactions
@@ -1049,7 +1339,6 @@ TupleTableSlot* ExecUpdate(ItemPointer tupleid,
             return NULL;
         }
 
-
         /* FDW might have changed tuple */
         tuple = ExecMaterializeSlot(slot);
     } else {
@@ -1102,7 +1391,8 @@ TupleTableSlot* ExecUpdate(ItemPointer tupleid,
                     &update_xmax,
                     estate->es_output_cid,
                     estate->es_crosscheck_snapshot,
-                    true /* wait for commit */);
+                    true /* wait for commit */,
+                    allow_update_self);
                 switch (result) {
                     case HeapTupleSelfUpdated:
                         /* can not update one row more than once for merge into */
@@ -1212,7 +1502,8 @@ TupleTableSlot* ExecUpdate(ItemPointer tupleid,
                  * If it's a HOT update, we mustn't insert new index entries.
                  */
                 if (result_rel_info->ri_NumIndices > 0 && !HeapTupleIsHeapOnly(tuple))
-                    recheck_indexes = ExecInsertIndexTuples(slot, &(tuple->t_self), estate, NULL, NULL, bucketid);
+                    recheck_indexes = ExecInsertIndexTuples(slot, &(tuple->t_self), estate,
+                        NULL, NULL, bucketid, NULL);
             } else {
             	/* for partitioned table */
                 bool row_movement = false;
@@ -1300,7 +1591,8 @@ TupleTableSlot* ExecUpdate(ItemPointer tupleid,
                         &update_xmax,
                         estate->es_output_cid,
                         estate->es_crosscheck_snapshot,
-                        true /* wait for commit */);
+                        true /* wait for commit */,
+                        allow_update_self);
                     switch (result) {
                         case HeapTupleSelfUpdated:
                             /* can not update one row more than once for merge into */
@@ -1403,7 +1695,7 @@ TupleTableSlot* ExecUpdate(ItemPointer tupleid,
                          * delete index entries for tuple
                          */
                         recheck_indexes = ExecInsertIndexTuples(slot, &(tuple->t_self), estate, 
-                            fake_part_rel, partition, bucketid);
+                            fake_part_rel, partition, bucketid, NULL);
                     }
                 } else {
                     /* row movement */
@@ -1432,7 +1724,8 @@ TupleTableSlot* ExecUpdate(ItemPointer tupleid,
                             &update_xmax,
                             estate->es_output_cid,
                             estate->es_crosscheck_snapshot,
-                            true /* wait for commit */);
+                            true /* wait for commit */,
+                            allow_update_self);
                         switch (result) {
                             case HeapTupleSelfUpdated:
                                 /* can not update one row more than once for merge into */
@@ -1541,7 +1834,7 @@ TupleTableSlot* ExecUpdate(ItemPointer tupleid,
 
                         if (result_rel_info->ri_NumIndices > 0) {
                             recheck_indexes = ExecInsertIndexTuples(
-                                slot, &(tuple->t_self), estate, fake_part_rel, insert_partition, bucketid);
+                                slot, &(tuple->t_self), estate, fake_part_rel, insert_partition, bucketid, NULL);
                         }
                     }
                 }
@@ -1602,6 +1895,9 @@ static void fireBSTriggers(ModifyTableState* node)
     switch (node->operation) {
         case CMD_INSERT:
             ExecBSInsertTriggers(node->ps.state, node->resultRelInfo);
+            if (node->mt_upsert->us_action == UPSERT_UPDATE) {
+                ExecBSUpdateTriggers(node->ps.state, node->resultRelInfo);
+            }
             break;
         case CMD_UPDATE:
             ExecBSUpdateTriggers(node->ps.state, node->resultRelInfo);
@@ -1629,6 +1925,9 @@ static void fireASTriggers(ModifyTableState* node)
     switch (node->operation) {
         case CMD_INSERT:
             ExecASInsertTriggers(node->ps.state, node->resultRelInfo);
+            if (node->mt_upsert->us_action == UPSERT_UPDATE) {
+                ExecASUpdateTriggers(node->ps.state, node->resultRelInfo);
+            }
             break;
         case CMD_UPDATE:
             ExecASUpdateTriggers(node->ps.state, node->resultRelInfo);
@@ -1755,7 +2054,7 @@ TupleTableSlot* ExecModifyTable(ModifyTableState* node)
 #endif
 
     if (operation == CMD_INSERT) {
-        if (node->ps.type == T_ModifyTableState ||
+        if (node->ps.type == T_ModifyTableState || node->mt_upsert->us_action != UPSERT_NONE ||
             (result_rel_info->ri_TrigDesc != NULL && (result_rel_info->ri_TrigDesc->trig_insert_before_row ||
                                                        result_rel_info->ri_TrigDesc->trig_insert_instead_row)))
             ExecInsert = ExecInsertT<false>;
@@ -2048,6 +2347,7 @@ ModifyTableState* ExecInitModifyTable(ModifyTable* node, EState* estate, int efl
     ResultRelInfo* result_rel_info = NULL;
     TupleDesc tup_desc = NULL;
     Plan* sub_plan = NULL;
+    UpsertState* upsertState = NULL;
     ListCell* l = NULL;
     int i;
 #ifdef PGXC
@@ -2110,6 +2410,13 @@ ModifyTableState* ExecInitModifyTable(ModifyTable* node, EState* estate, int efl
     mt_state->mt_arowmarks = (List**)palloc0(sizeof(List*) * nplans);
     mt_state->mt_nplans = nplans;
 
+    upsertState = (UpsertState*)palloc0(sizeof(UpsertState));
+    upsertState->us_action = node->upsertAction;
+    upsertState->us_existing = NULL;
+    upsertState->us_excludedtlist = NIL;
+    upsertState->us_updateproj = NULL;
+    mt_state->mt_upsert = upsertState;
+
     /* set up epqstate with dummy sub_plan data for the moment */
     EvalPlanQualInit(&mt_state->mt_epqstate, estate, NULL, NIL, node->epqParam);
     mt_state->fireBSTriggers = true;
@@ -2160,7 +2467,7 @@ ModifyTableState* ExecInitModifyTable(ModifyTable* node, EState* estate, int efl
             result_rel_info->ri_IndexRelationDescs == NULL) {
             if (result_rel_info->ri_FdwRoutine == NULL || result_rel_info->ri_FdwRoutine->GetFdwType == NULL ||
                     result_rel_info->ri_FdwRoutine->GetFdwType() != MOT_ORC)
-                ExecOpenIndices(result_rel_info);
+                ExecOpenIndices(result_rel_info, node->upsertAction != UPSERT_NONE);
         }
         init_gtt_storage(operation, result_rel_info);
         /* Now init the plan for this result rel */
@@ -2281,6 +2588,43 @@ ModifyTableState* ExecInitModifyTable(ModifyTable* node, EState* estate, int efl
         mt_state->ps.ps_ExprContext = NULL;
     }
 
+    /*
+     * If needed, Initialize target list, projection and qual for DUPLICATE KEY UPDATE
+     */
+    result_rel_info = mt_state->resultRelInfo;
+    if (node->upsertAction == UPSERT_UPDATE) {
+        ExprContext* econtext;
+        ExprState* setexpr;
+        TupleDesc tupDesc;
+
+        /* insert may only have one plan, inheritance is not expanded */
+        Assert(nplans = 1);
+
+        /* already exists if created by RETURNING processing above */
+        if (mt_state->ps.ps_ExprContext == NULL) {
+            ExecAssignExprContext(estate, &mt_state->ps);
+        }
+
+        econtext = mt_state->ps.ps_ExprContext;
+
+        /* initialize slot for the existing tuple */
+        upsertState->us_existing = ExecInitExtraTupleSlot(mt_state->ps.state);
+        ExecSetSlotDescriptor(upsertState->us_existing, result_rel_info->ri_RelationDesc->rd_att);
+
+        upsertState->us_excludedtlist = node->exclRelTlist;
+
+        /* create target slot for UPDATE SET projection */
+        tupDesc = ExecTypeFromTL((List*)node->updateTlist, result_rel_info->ri_RelationDesc->rd_rel->relhasoids);
+        upsertState->us_updateproj = ExecInitExtraTupleSlot(mt_state->ps.state);
+        ExecSetSlotDescriptor(upsertState->us_updateproj, tupDesc);
+
+        /* build UPDATE SET expression and projection state */
+        setexpr = ExecInitExpr((Expr*)node->updateTlist, &mt_state->ps);
+        result_rel_info->ri_updateProj =
+        ExecBuildProjectionInfo((List*)setexpr, econtext,
+            upsertState->us_updateproj, result_rel_info->ri_RelationDesc->rd_att);
+    }
+
     /*
      * If we have any secondary relations in an UPDATE or DELETE, they need to
      * be treated like non-locked relations in SELECT FOR UPDATE, ie, the
diff --git a/src/gausskernel/runtime/executor/opfusion.cpp b/src/gausskernel/runtime/executor/opfusion.cpp
index cfa5d6cf3..171d41604 100644
--- a/src/gausskernel/runtime/executor/opfusion.cpp
+++ b/src/gausskernel/runtime/executor/opfusion.cpp
@@ -1075,7 +1075,7 @@ bool InsertFusion::execute(long max_rows, char* completionTag)
     m_estate->es_result_relation_info = result_rel_info;
 
     if (result_rel_info->ri_RelationDesc->rd_rel->relhasindex) {
-        ExecOpenIndices(result_rel_info);
+        ExecOpenIndices(result_rel_info, false);
     }
 
     CommandId mycid = GetCurrentCommandId(true);
@@ -1109,7 +1109,7 @@ bool InsertFusion::execute(long max_rows, char* completionTag)
     /* insert index entries for tuple */
     List* recheck_indexes = NIL;
     if (result_rel_info->ri_NumIndices > 0) {
-        recheck_indexes = ExecInsertIndexTuples(m_reslot, &(tuple->t_self), m_estate, NULL, NULL, bucketid);
+        recheck_indexes = ExecInsertIndexTuples(m_reslot, &(tuple->t_self), m_estate, NULL, NULL, bucketid, NULL);
     }
     list_free_ext(recheck_indexes);
 
@@ -1388,7 +1388,7 @@ bool UpdateFusion::execute(long max_rows, char* completionTag)
     m_estate->es_output_cid = GetCurrentCommandId(true);
 
     if (result_rel_info->ri_RelationDesc->rd_rel->relhasindex) {
-        ExecOpenIndices(result_rel_info);
+        ExecOpenIndices(result_rel_info, false);
     }
 
     /*********************************
@@ -1443,7 +1443,8 @@ bool UpdateFusion::execute(long max_rows, char* completionTag)
                 /* done successfully */
                 nprocessed++;
                 if (result_rel_info->ri_NumIndices > 0 && !HeapTupleIsHeapOnly(tup)) {
-                    recheck_indexes = ExecInsertIndexTuples(m_reslot, &(tup->t_self), m_estate, NULL, NULL, bucketid);
+                    recheck_indexes = ExecInsertIndexTuples(m_reslot, &(tup->t_self), m_estate,
+                        NULL, NULL, bucketid, NULL);
                     list_free_ext(recheck_indexes);
                 }
                 break;
@@ -1574,7 +1575,7 @@ bool DeleteFusion::execute(long max_rows, char* completionTag)
     m_estate->es_output_cid = GetCurrentCommandId(true);
 
     if (result_rel_info->ri_RelationDesc->rd_rel->relhasindex) {
-        ExecOpenIndices(result_rel_info);
+        ExecOpenIndices(result_rel_info, false);
     }
 
     /********************************
@@ -1781,7 +1782,7 @@ bool SelectForUpdateFusion::execute(long max_rows, char* completionTag)
     m_estate->es_output_cid = GetCurrentCommandId(true);
 
     if (result_rel_info->ri_RelationDesc->rd_rel->relhasindex) {
-        ExecOpenIndices(result_rel_info);
+        ExecOpenIndices(result_rel_info, false);
     }
 
     /**************************************
@@ -1850,6 +1851,10 @@ bool SelectForUpdateFusion::execute(long max_rows, char* completionTag)
             }
 
             switch (result) {
+                case HeapTupleSelfCreated:
+                    ereport(ERROR, (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
+                        errmsg("attempted to lock invisible tuple")));
+                    break;
                 case HeapTupleSelfUpdated:
                     /* already deleted by self; nothing to do */
                     break;
diff --git a/src/gausskernel/runtime/executor/opfusion_util.cpp b/src/gausskernel/runtime/executor/opfusion_util.cpp
index 7541bc5f7..f2be66e1a 100755
--- a/src/gausskernel/runtime/executor/opfusion_util.cpp
+++ b/src/gausskernel/runtime/executor/opfusion_util.cpp
@@ -208,6 +208,11 @@ const char *getBypassReason(FusionType result)
             break;
         }
 
+        case NOBYPASS_UPSERT_NOT_SUPPORT: {
+            return "Bypass not support INSERT INTO ... ON DUPLICATE KEY UPDATE statement";
+            break;
+        }
+
         default: {
             Assert(0);
             ereport(ERROR,
@@ -757,6 +762,9 @@ FusionType getInsertFusionType(List *stmt_list, ParamListInfo params)
     if (base->plan.lefttree != NULL || base->plan.initPlan != NIL || base->resconstantqual != NULL) {
         return NOBYPASS_NO_SIMPLE_INSERT;
     }
+    if (node->upsertAction != UPSERT_NONE) {
+        return NOBYPASS_UPSERT_NOT_SUPPORT;
+    }
 
     /* check relation */
     Index res_rel_idx = linitial_int(plannedstmt->resultRelations);
diff --git a/src/gausskernel/storage/access/heap/heapam.cpp b/src/gausskernel/storage/access/heap/heapam.cpp
index 4605999b7..e0d71c3a2 100644
--- a/src/gausskernel/storage/access/heap/heapam.cpp
+++ b/src/gausskernel/storage/access/heap/heapam.cpp
@@ -2547,7 +2547,7 @@ Oid heap_insert(Relation relation, HeapTuple tup, CommandId cid, int options, Bu
         }
 
         xlrec.offnum = ItemPointerGetOffsetNumber(&heaptup->t_self);
-        xlrec.flags = all_visible_cleared ? XLOG_HEAP_ALL_VISIBLE_CLEARED : 0;
+        xlrec.flags = all_visible_cleared ? XLH_INSERT_ALL_VISIBLE_CLEARED : 0;
         Assert(ItemPointerGetBlockNumber(&heaptup->t_self) == BufferGetBlockNumber(buffer));
 
         /*
@@ -2556,7 +2556,7 @@ Oid heap_insert(Relation relation, HeapTuple tup, CommandId cid, int options, Bu
          * image. (XXX We could alternatively store a pointer into the FPW).
          */
         if (RelationIsLogicallyLogged(relation)) {
-            xlrec.flags |= XLOG_HEAP_CONTAINS_NEW_TUPLE;
+            xlrec.flags |= XLH_INSERT_CONTAINS_NEW_TUPLE;
             bufflags |= REGBUF_KEEP_DATA;
         }
 
@@ -2605,6 +2605,7 @@ Oid heap_insert(Relation relation, HeapTuple tup, CommandId cid, int options, Bu
      */
     CacheInvalidateHeapTuple(relation, heaptup, NULL);
 
+    /* Note: speculative insertions are counted too, even if aborted later */
     pgstat_count_heap_insert(relation, 1);
 
     /*
@@ -2619,7 +2620,145 @@ Oid heap_insert(Relation relation, HeapTuple tup, CommandId cid, int options, Bu
     return HeapTupleGetOid(tup);
 }
 
-/**
+/*
+ * heap_abort_speculative - kill a speculatively inserted tuple
+ *
+ * Marks a tuple that was speculatively inserted in the same command as dead,
+ * by setting its xmin as invalid.  That makes it immediately appear as dead
+ * to all transactions, including our own.  In particular, it makes
+ * HeapTupleSatisfiesDirty() regard the tuple as dead, so that another backend
+ * inserting a duplicate key value won't unnecessarily wait for our whole
+ * transaction to finish (it'll just wait for our speculative insertion to
+ * finish).
+ *
+ * Killing the tuple prevents "unprincipled deadlocks", which are deadlocks
+ * that arise due to a mutual dependency that is not user visible.  By
+ * definition, unprincipled deadlocks cannot be prevented by the user
+ * reordering lock acquisition in client code, because the implementation level
+ * lock acquisitions are not under the user's direct control.  If speculative
+ * inserters did not take this precaution, then under high concurrency they
+ * could deadlock with each other, which would not be acceptable.
+ *
+ * This is somewhat redundant with heap_delete, but we prefer to have a
+ * dedicated routine with stripped down requirements.
+ *
+ * This routine does not affect logical decoding as it only looks at
+ * confirmation records.
+ */
+void heap_abort_speculative(Relation relation, HeapTuple tuple)
+{
+    TransactionId xid = GetCurrentTransactionId();
+    ItemPointer tid = &(tuple->t_self);
+    ItemId      lp;
+    HeapTupleData tp;
+    Page        page;
+    BlockNumber block;
+    Buffer      buffer;
+
+    Assert(ItemPointerIsValid(tid));
+
+    block = ItemPointerGetBlockNumber(tid);
+    buffer = ReadBuffer(relation, block);
+    page = BufferGetPage(buffer);
+
+    LockBuffer(buffer, BUFFER_LOCK_EXCLUSIVE);
+
+    /*
+     * Page can't be all visible, we just inserted into it, and are still
+     * running.
+     */
+    Assert(!PageIsAllVisible(page));
+
+    lp = PageGetItemId(page, ItemPointerGetOffsetNumber(tid));
+    Assert(ItemIdIsNormal(lp));
+
+    tp.t_tableOid = RelationGetRelid(relation);
+    tp.t_data = (HeapTupleHeader) PageGetItem(page, lp);
+    tp.t_len = ItemIdGetLength(lp);
+    tp.t_self = *tid;
+
+    /*
+     * Sanity check that the tuple really is a speculatively inserted tuple,
+     * inserted by us.
+     */
+    if (HeapTupleHeaderGetXmin(page, tp.t_data) != xid) {
+        ereport(ERROR,
+            (errmsg("attempted to kill a tuple inserted by another transaction: %lu, %lu",
+             HeapTupleGetRawXmin(&tp), xid)));
+    }
+    Assert(!HeapTupleHeaderIsHeapOnly(tp.t_data));
+
+    /*
+     * No need to check for serializable conflicts here.  There is never a
+     * need for a combocid, either.  No need to extract replica identity, or
+     * do anything special with infomask bits.
+     */
+    START_CRIT_SECTION();
+
+    /*
+     * The tuple will become DEAD immediately.  Flag that this page
+     * immediately is a candidate for pruning by setting xmin to
+     * RecentGlobalXmin.  That's not pretty, but it doesn't seem worth
+     * inventing a nicer API for this.
+     */
+    PageSetPrunable(page, xid);
+
+    /* store transaction information of xact deleting the tuple */
+    tp.t_data->t_infomask &= ~(HEAP_XMAX_COMMITTED | HEAP_XMAX_INVALID | HEAP_XMAX_IS_MULTI |
+                               HEAP_IS_LOCKED | HEAP_MOVED);
+
+    /*
+     * Set the tuple header xmin to InvalidTransactionId.  This makes the
+     * tuple immediately invisible everyone.  (In particular, to any
+     * transactions waiting on the speculative token, woken up later.)
+     */
+    HeapTupleHeaderSetXmin(page, tp.t_data, InvalidTransactionId);
+
+    MarkBufferDirty(buffer);
+
+    /*
+     * XLOG stuff
+     *
+     * The WAL records generated here match heap_delete().  The same recovery
+     * routines are used.
+     */
+    if (RelationNeedsWAL(relation)) {
+        xl_heap_delete xlrec;
+        XLogRecPtr  recptr;
+
+        xlrec.flags = XLH_DELETE_IS_SUPER;
+        xlrec.offnum = ItemPointerGetOffsetNumber(&tp.t_self);
+
+        XLogBeginInsert();
+        XLogRegisterData((char *) &xlrec, SizeOfHeapDelete);
+        XLogRegisterBuffer(0, buffer, REGBUF_STANDARD);
+
+        /* No replica identity & replication origin logged */
+        recptr = XLogInsert(RM_HEAP_ID, XLOG_HEAP_DELETE);
+
+        PageSetLSN(page, recptr);
+    }
+
+    END_CRIT_SECTION();
+
+    LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
+
+    if (HeapTupleHasExternal(&tp))
+        toast_delete(relation, &tp, HEAP_INSERT_SPECULATIVE);
+
+    /*
+     * Never need to mark tuple for invalidation, since catalogs don't support
+     * speculative insertion
+     */
+
+    /* Now we can release the buffer */
+    ReleaseBuffer(buffer);
+
+    /* count deletion, as we counted the insertion too */
+    pgstat_count_heap_delete(relation);
+}
+
+/*
  * @Description: Find minimum and maximum short transaction ids which occurs in the page.
  * @in: page, heap page
  * @in: multi, Whether multixact
@@ -3422,7 +3561,7 @@ int heap_multi_insert(Relation relation, Relation parent, HeapTuple* tuples, int
             /* the rest of the scratch space is used for tuple data */
             tuple_data = scratchptr;
 
-            xlrec->flags = all_visible_cleared ? XLOG_HEAP_ALL_VISIBLE_CLEARED : 0;
+            xlrec->flags = all_visible_cleared ? XLH_INSERT_ALL_VISIBLE_CLEARED : 0;
             xlrec->ntuples = nthispage;
 
             /* xlog: write the dictionary between header and tuples */
@@ -3472,7 +3611,7 @@ int heap_multi_insert(Relation relation, Relation parent, HeapTuple* tuples, int
             Assert((scratchptr - scratch) < BLCKSZ);
 
             if (need_tuple_data) {
-                xlrec->flags |= XLOG_HEAP_CONTAINS_NEW_TUPLE;
+                xlrec->flags |= XLH_INSERT_CONTAINS_NEW_TUPLE;
             }
 
             /*
@@ -3481,7 +3620,7 @@ int heap_multi_insert(Relation relation, Relation parent, HeapTuple* tuples, int
              * decoding so it knows when to cleanup temporary data.
              */
             if (ndone + nthispage == ntuples) {
-                xlrec->flags |= XLOG_HEAP_LAST_MULTI_INSERT;
+                xlrec->flags |= XLH_INSERT_LAST_IN_MULTI;
             }
 
             /*
@@ -3620,7 +3759,7 @@ Oid simple_heap_insert(Relation relation, HeapTuple tup)
  * (t_xmax is needed to verify that the replacement tuple matches.)
  */
 HTSU_Result heap_delete(Relation relation, ItemPointer tid, ItemPointer ctid, TransactionId* update_xmax, CommandId cid,
-    Snapshot crosscheck, bool wait)
+    Snapshot crosscheck, bool wait, bool allow_delete_self)
 {
     HTSU_Result result;
     TransactionId xid = GetCurrentTransactionId();
@@ -3694,11 +3833,16 @@ HTSU_Result heap_delete(Relation relation, ItemPointer tid, ItemPointer ctid, Tr
     HeapTupleCopyBaseFromPage(&tp, page);
 
 l1:
-    result = HeapTupleSatisfiesUpdate(&tp, cid, buffer);
+    result = HeapTupleSatisfiesUpdate(&tp, cid, buffer, allow_delete_self);
 
     if (result == HeapTupleInvisible) {
         UnlockReleaseBuffer(buffer);
         ereport(ERROR, (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE), errmsg("attempted to delete invisible tuple")));
+    } else if (result == HeapTupleSelfCreated) {
+        UnlockReleaseBuffer(buffer);
+        /* if allow self delete, HeapTupleSelfCreated status will never be reached */
+        Assert(!allow_delete_self);
+        ereport(ERROR, (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE), errmsg("attempted to delete self created tuple")));
     } else if (result == HeapTupleBeingUpdated && wait) {
         TransactionId xwait;
         uint16 infomask;
@@ -3866,7 +4010,7 @@ l1:
             (void)log_heap_new_cid(relation, &tp);
         }
 
-        xlrec.flags = all_visible_cleared ? XLOG_HEAP_ALL_VISIBLE_CLEARED : 0;
+        xlrec.flags = all_visible_cleared ? XLH_DELETE_ALL_VISIBLE_CLEARED : 0;
         xlrec.offnum = ItemPointerGetOffsetNumber(&tp.t_self);
 
         if (old_key_tuple != NULL) {
@@ -3890,9 +4034,9 @@ l1:
             }
 
             if (relreplident == REPLICA_IDENTITY_FULL) {
-                xlrec.flags |= XLOG_HEAP_CONTAINS_OLD_TUPLE;
+                xlrec.flags |= XLH_DELETE_CONTAINS_OLD_TUPLE;
             } else {
-                xlrec.flags |= XLOG_HEAP_CONTAINS_OLD_KEY;
+                xlrec.flags |= XLH_DELETE_CONTAINS_OLD_KEY;
             }
         }
 
@@ -3940,7 +4084,7 @@ l1:
         /* toast table entries should never be recursively toasted */
         Assert(!HeapTupleHasExternal(&tp));
     } else if (HeapTupleHasExternal(&tp))
-        toast_delete(relation, &tp);
+        toast_delete(relation, &tp, allow_delete_self ? HEAP_INSERT_SPECULATIVE : 0);
 
     /*
      * Mark tuple for invalidation from system caches at next command
@@ -3976,11 +4120,12 @@ l1:
  * on the relation associated with the tuple).	Any failure is reported
  * via ereport().
  */
-void simple_heap_delete(Relation relation, ItemPointer tid)
+void simple_heap_delete(Relation relation, ItemPointer tid, int options)
 {
     HTSU_Result result;
     ItemPointerData update_ctid;
     TransactionId update_xmax;
+    bool allow_delete_self = (options & HEAP_INSERT_SPECULATIVE) ? true : false;
 
     result = heap_delete(relation,
         tid,
@@ -3988,7 +4133,8 @@ void simple_heap_delete(Relation relation, ItemPointer tid)
         &update_xmax,
         GetCurrentCommandId(true),
         InvalidSnapshot,
-        true /* wait for commit */);
+        true /* wait for commit */,
+        allow_delete_self);
     switch (result) {
         case HeapTupleSelfUpdated:
             /* Tuple was already updated in current command? */
@@ -4042,8 +4188,9 @@ void simple_heap_delete(Relation relation, ItemPointer tid)
  * tuple was updated, and t_ctid is the location of the replacement tuple.
  * (t_xmax is needed to verify that the replacement tuple matches.)
  */
-HTSU_Result heap_update(Relation relation, Relation parentRelation, ItemPointer otid, HeapTuple newtup,
-    ItemPointer ctid, TransactionId* update_xmax, CommandId cid, Snapshot crosscheck, bool wait)
+HTSU_Result heap_update(Relation relation, Relation parentRelation, ItemPointer otid,
+    HeapTuple newtup, ItemPointer ctid, TransactionId* update_xmax, CommandId cid,
+    Snapshot crosscheck, bool wait, bool allow_update_self)
 {
     HTSU_Result result;
     TransactionId xid = GetCurrentTransactionId();
@@ -4144,10 +4291,15 @@ HTSU_Result heap_update(Relation relation, Relation parentRelation, ItemPointer
 
 l2:
     HeapTupleCopyBaseFromPage(&oldtup, BufferGetPage(buffer));
-    result = HeapTupleSatisfiesUpdate(&oldtup, cid, buffer);
+    result = HeapTupleSatisfiesUpdate(&oldtup, cid, buffer, allow_update_self);
     if (result == HeapTupleInvisible) {
         UnlockReleaseBuffer(buffer);
         ereport(ERROR, (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE), errmsg("attempted to update invisible tuple")));
+    } else if (result == HeapTupleSelfCreated) {
+        UnlockReleaseBuffer(buffer);
+        /* if allow self update, HeapTupleSelfCreated status will never be reached */
+        Assert(!allow_update_self);
+        ereport(ERROR, (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE), errmsg("attempted to update self created tuple")));
     } else if (result == HeapTupleBeingUpdated && wait) {
         TransactionId xwait;
         uint16 infomask;
@@ -4386,7 +4538,8 @@ l2:
          */
         if (need_toast) {
             /* Note we always use WAL and FSM during updates */
-            heaptup = toast_insert_or_update(relation, newtup, &oldtup, 0, page);
+            heaptup = toast_insert_or_update(relation, newtup, &oldtup,
+                allow_update_self ? HEAP_INSERT_SPECULATIVE : 0, page);
             new_tup_size = MAXALIGN(heaptup->t_len);
         } else {
             heaptup = newtup;
@@ -5064,7 +5217,7 @@ void simple_heap_update(Relation relation, ItemPointer otid, HeapTuple tup)
  * conflict for a tuple, we don't incur any extra overhead.
  */
 HTSU_Result heap_lock_tuple(Relation relation, HeapTuple tuple, Buffer* buffer, ItemPointer ctid,
-    TransactionId* update_xmax, CommandId cid, LockTupleMode mode, bool nowait)
+    TransactionId* update_xmax, CommandId cid, LockTupleMode mode, bool nowait, bool allow_lock_self)
 {
     HTSU_Result result;
     ItemPointer tid = &(tuple->t_self);
@@ -5122,7 +5275,7 @@ HTSU_Result heap_lock_tuple(Relation relation, HeapTuple tuple, Buffer* buffer,
 
 l3:
     HeapTupleCopyBaseFromPage(tuple, page);
-    result = HeapTupleSatisfiesUpdate(tuple, cid, *buffer);
+    result = HeapTupleSatisfiesUpdate(tuple, cid, *buffer, allow_lock_self);
     ereport(DEBUG1,
         (errmsg("heap lock tuple ctid (%u,%d) cur_xid %lu xmin "
                 "%lu xmax %lu infomask %hu result %d",
@@ -5137,6 +5290,25 @@ l3:
     if (result == HeapTupleInvisible) {
         UnlockReleaseBuffer(*buffer);
         ereport(ERROR, (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE), errmsg("attempted to lock invisible tuple")));
+    } else if (result == HeapTupleSelfCreated) {
+        /*
+         * This is possible when the tuple is going to be updated twice in one command,
+         * which should be considered as invisible (same with HeapTupleInvisible) and
+         * throw an error.
+         *
+         * However, there is a special case: UPSERT multiple VALUES using a STREAM plan
+         * e.g INSERT values(1,x),(1,x) ON DUPLICATE KEY UPDATE..
+         * As we have to allow this case to be done in MYSQL compatibility,
+         * we return HeapTupleSelfCreated here rather than throwing an error in
+         * order to give UPSERT case the opportunity to throw a more specific error or
+         * allow to UPSERT
+         *
+         * NOTE: multiple VALUES UPSERT using a PGXC plan is not a problem because
+         * the optimizer will spilt the query into multiple commands, each of which only
+         * UPSERT one VALUES().
+         */
+        LockBuffer(*buffer, BUFFER_LOCK_UNLOCK);
+        return HeapTupleSelfCreated;
     } else if (result == HeapTupleBeingUpdated) {
         TransactionId xwait;
         uint16 infomask;
@@ -6040,18 +6212,18 @@ static XLogRecPtr log_heap_update(Relation reln, Buffer oldbuf, const ItemPointe
     xlrec.new_offnum = ItemPointerGetOffsetNumber(&newtup->t_self);
     xlrec.flags = 0;
     if (all_visible_cleared) {
-        xlrec.flags |= XLOG_HEAP_ALL_VISIBLE_CLEARED;
+        xlrec.flags |= XLH_UPDATE_OLD_ALL_VISIBLE_CLEARED;
     }
     if (new_all_visible_cleared) {
-        xlrec.flags |= XLOG_HEAP_NEW_ALL_VISIBLE_CLEARED;
+        xlrec.flags |= XLH_UPDATE_NEW_ALL_VISIBLE_CLEARED;
     }
     if (need_tuple_data) {
-        xlrec.flags |= XLOG_HEAP_CONTAINS_NEW_TUPLE;
+        xlrec.flags |= XLH_UPDATE_CONTAINS_NEW_TUPLE;
         if (old_key_tuple) {
             if (reln->rd_rel->relreplident == REPLICA_IDENTITY_FULL)
-                xlrec.flags |= XLOG_HEAP_CONTAINS_OLD_TUPLE;
+                xlrec.flags |= XLH_UPDATE_CONTAINS_OLD_TUPLE;
             else
-                xlrec.flags |= XLOG_HEAP_CONTAINS_OLD_KEY;
+                xlrec.flags |= XLH_UPDATE_CONTAINS_OLD_KEY;
         }
     }
     if (need_tuple_data) {
@@ -6717,7 +6889,7 @@ static void heap_xlog_delete(XLogReaderState* record)
      * The visibility map may need to be fixed even if the heap page is
      * already up-to-date.
      */
-    if (xlrec->flags & XLOG_HEAP_ALL_VISIBLE_CLEARED) {
+    if (xlrec->flags & XLH_DELETE_ALL_VISIBLE_CLEARED) {
         RelFileNode target_node;
         BlockNumber blkno;
 
@@ -6759,7 +6931,7 @@ static void heap_xlog_insert(XLogReaderState* record)
      * The visibility map may need to be fixed even if the heap page is
      * already up-to-date.
      */
-    if (xlrec->flags & XLOG_HEAP_ALL_VISIBLE_CLEARED) {
+    if (xlrec->flags & XLH_INSERT_ALL_VISIBLE_CLEARED) {
         heap_xlog_allvisiblecleared(target_node, blkno);
     }
 
@@ -6832,7 +7004,7 @@ static void heap_xlog_multi_insert(XLogReaderState* record)
      * The visibility map may need to be fixed even if the heap page is
      * already up-to-date.
      */
-    if (xlrec->flags & XLOG_HEAP_ALL_VISIBLE_CLEARED) {
+    if (xlrec->flags & XLH_INSERT_ALL_VISIBLE_CLEARED) {
         heap_xlog_allvisiblecleared(rnode, blkno);
     }
 
@@ -6902,12 +7074,11 @@ static void heap_xlog_update(XLogReaderState* record, bool hot_update)
         oldblk = newblk;
     }
 
-
     /*
      * The visibility map may need to be fixed even if the heap page is
      * already up-to-date.
      */
-    if (xlrec->flags & XLOG_HEAP_ALL_VISIBLE_CLEARED) {
+    if (xlrec->flags & XLH_UPDATE_OLD_ALL_VISIBLE_CLEARED) {
         heap_xlog_allvisiblecleared(rnode, oldblk);
     }
 
@@ -6949,7 +7120,7 @@ static void heap_xlog_update(XLogReaderState* record, bool hot_update)
      * The visibility map may need to be fixed even if the heap page is
      * already up-to-date.
      */
-    if (xlrec->flags & XLOG_HEAP_NEW_ALL_VISIBLE_CLEARED) {
+    if (xlrec->flags & XLH_UPDATE_NEW_ALL_VISIBLE_CLEARED) {
         heap_xlog_allvisiblecleared(rnode, newblk);
     }
 
diff --git a/src/gausskernel/storage/access/heap/tuptoaster.cpp b/src/gausskernel/storage/access/heap/tuptoaster.cpp
index c1a5d5a83..a07bac7dd 100644
--- a/src/gausskernel/storage/access/heap/tuptoaster.cpp
+++ b/src/gausskernel/storage/access/heap/tuptoaster.cpp
@@ -45,7 +45,7 @@
 
 #undef TOAST_DEBUG
 
-static void toast_delete_datum(Relation rel, Datum value);
+static void toast_delete_datum(Relation rel, Datum value, int options);
 static Datum toast_save_datum(Relation rel, Datum value, struct varlena* oldexternal, int options);
 static bool toastid_valueid_exists(Oid toastrelid, Oid valueid, int2 bucketid);
 static struct varlena* toast_fetch_datum(struct varlena* attr);
@@ -332,7 +332,7 @@ Size toast_datum_size(Datum value)
  *	Cascaded delete toast-entries on DELETE
  * ----------
  */
-void toast_delete(Relation rel, HeapTuple oldtup)
+void toast_delete(Relation rel, HeapTuple oldtup, int options)
 {
     TupleDesc tuple_desc;
     Form_pg_attribute* att = NULL;
@@ -381,7 +381,7 @@ void toast_delete(Relation rel, HeapTuple oldtup)
             if (toast_isnull[i])
                 continue;
             else if (VARATT_IS_EXTERNAL_ONDISK_B(PointerGetDatum(value)))
-                toast_delete_datum(rel, value);
+                toast_delete_datum(rel, value, options);
             else if (VARATT_IS_EXTERNAL_INDIRECT(PointerGetDatum(value)))
                 ereport(ERROR,
                     (errcode(ERRCODE_FETCH_DATA_FAILED), errmsg("attempt to delete tuple containing indirect datums")));
@@ -931,7 +931,7 @@ HeapTuple toast_insert_or_update(Relation rel, HeapTuple newtup, HeapTuple oldtu
     if (need_delold) {
         for (i = 0; i < num_attrs; i++) {
             if (toast_delold[i]) {
-                toast_delete_datum(rel, toast_oldvalues[i]);
+                toast_delete_datum(rel, toast_oldvalues[i], options);
             }
         }
     }
@@ -1461,7 +1461,7 @@ static Datum toast_save_datum(Relation rel, Datum value, struct varlena* oldexte
  *	Delete a single external stored value.
  * ----------
  */
-static void toast_delete_datum(Relation rel, Datum value)
+static void toast_delete_datum(Relation rel, Datum value, int options)
 {
     struct varlena* attr = (struct varlena*)DatumGetPointer(value);
     struct varatt_external toast_pointer;
@@ -1501,7 +1501,7 @@ static void toast_delete_datum(Relation rel, Datum value)
         /*
          * Have a chunk, delete it
          */
-        simple_heap_delete(toastrel, &toasttup->t_self);
+        simple_heap_delete(toastrel, &toasttup->t_self, options);
 
         if (u_sess->attr.attr_storage.enable_debug_vacuum)
             elogVacuumInfo(toastrel, toasttup, "toast_delete_datum", u_sess->cmd_cxt.OldestXmin);
diff --git a/src/gausskernel/storage/access/redo/heapam.cpp b/src/gausskernel/storage/access/redo/heapam.cpp
index 42fc6d1bd..0388973cd 100644
--- a/src/gausskernel/storage/access/redo/heapam.cpp
+++ b/src/gausskernel/storage/access/redo/heapam.cpp
@@ -367,7 +367,7 @@ void heap_xlog_delete_operator_page(RedoBufferInfo* buffer, void* recorddata, Tr
     /* Mark the page as a candidate for pruning */
     PageSetPrunable(page, recordxid);
 
-    if (xlrec->flags & XLOG_HEAP_ALL_VISIBLE_CLEARED)
+    if (xlrec->flags & XLH_INSERT_ALL_VISIBLE_CLEARED)
         PageClearAllVisible(page);
 
     /* Make sure there is no forward chain link in t_ctid */
@@ -445,7 +445,7 @@ void heap_xlog_insert_operator_page(RedoBufferInfo* buffer, void* recorddata, bo
 
     PageSetLSN(page, buffer->lsn);
 
-    if (xlrec->flags & XLOG_HEAP_ALL_VISIBLE_CLEARED)
+    if (xlrec->flags & XLH_INSERT_ALL_VISIBLE_CLEARED)
         PageClearAllVisible(page);
 }
 
@@ -548,7 +548,7 @@ void heap_xlog_multi_insert_operator_page(RedoBufferInfo* buffer, void* recoredd
 
     PageSetLSN(page, buffer->lsn);
 
-    if (xlrec->flags & XLOG_HEAP_ALL_VISIBLE_CLEARED)
+    if (xlrec->flags & XLH_INSERT_ALL_VISIBLE_CLEARED)
         PageClearAllVisible(page);
 }
 
@@ -592,7 +592,7 @@ void heap_xlog_update_operator_oldpage(RedoBufferInfo* buffer, void* recoreddata
     /* Mark the page as a candidate for pruning */
     PageSetPrunable(page, recordxid);
 
-    if (xlrec->flags & XLOG_HEAP_ALL_VISIBLE_CLEARED)
+    if (xlrec->flags & XLH_INSERT_ALL_VISIBLE_CLEARED)
         PageClearAllVisible(page);
 
     PageHeader oldPhdr = (PageHeader)page;
@@ -708,7 +708,7 @@ void heap_xlog_update_operator_newpage(RedoBufferInfo* buffer, void* recorddata,
     if (PageAddItem(page, (Item)htup, newlen, xlrec->new_offnum, true, true) == InvalidOffsetNumber)
         ereport(PANIC, (errmsg("heap_update_redo: failed to add tuple")));
 
-    if (xlrec->flags & XLOG_HEAP_NEW_ALL_VISIBLE_CLEARED)
+    if (xlrec->flags & XLH_UPDATE_NEW_ALL_VISIBLE_CLEARED)
         PageClearAllVisible(page);
     if (freespace != NULL) {
         *freespace = PageGetHeapFreeSpace(page);
@@ -889,7 +889,7 @@ static XLogRecParseState* heap_xlog_insert_parse_block(XLogReaderState* record,
     }
     xlrec = (xl_heap_insert*)rec_data;
 
-    if (xlrec->flags & XLOG_HEAP_ALL_VISIBLE_CLEARED) {
+    if (xlrec->flags & XLH_INSERT_ALL_VISIBLE_CLEARED) {
         (*blocknum)++;
         XLogParseBufferAllocListFunc(record, &blockstate, recordstatehead);
         if (blockstate == NULL) {
@@ -915,7 +915,7 @@ static XLogRecParseState* heap_xlog_delete_parse_block(XLogReaderState* record,
 
     XLogRecSetBlockDataState(record, HEAP_DELETE_ORIG_BLOCK_NUM, recordstatehead);
 
-    if (xlrec->flags & XLOG_HEAP_ALL_VISIBLE_CLEARED) {
+    if (xlrec->flags & XLH_INSERT_ALL_VISIBLE_CLEARED) {
         (*blocknum)++;
         XLogParseBufferAllocListFunc(record, &blockstate, recordstatehead);
         if (blockstate == NULL) {
@@ -973,7 +973,7 @@ static XLogRecParseState* heap_xlog_update_parse_block(XLogReaderState* record,
         XLogRecSetAuxiBlkNumState(&blockstate->blockparse.extra_rec.blockdatarec, newblk, InvalidForkNumber);
         // OLD BLOCK
 
-        if (xlrec->flags & XLOG_HEAP_ALL_VISIBLE_CLEARED) {
+        if (xlrec->flags & XLH_INSERT_ALL_VISIBLE_CLEARED) {
             (*blocknum)++;
             XLogParseBufferAllocListFunc(record, &blockstate, recordstatehead);
             if (blockstate == NULL) {
@@ -985,8 +985,8 @@ static XLogRecParseState* heap_xlog_update_parse_block(XLogReaderState* record,
         }
     }
 
-    if ((xlrec->flags & XLOG_HEAP_NEW_ALL_VISIBLE_CLEARED) ||
-        ((oldblk == newblk) && (xlrec->flags & XLOG_HEAP_ALL_VISIBLE_CLEARED))) {
+    if ((xlrec->flags & XLH_UPDATE_NEW_ALL_VISIBLE_CLEARED) ||
+        ((oldblk == newblk) && (xlrec->flags & XLH_INSERT_ALL_VISIBLE_CLEARED))) {
         (*blocknum)++;
         XLogParseBufferAllocListFunc(record, &blockstate, recordstatehead);
         if (blockstate == NULL) {
@@ -1279,7 +1279,7 @@ static XLogRecParseState* heap_xlog_multi_insert_parse_block(XLogReaderState* re
     }
     xlrec = (xl_heap_multi_insert*)rec_data;
 
-    if (xlrec->flags & XLOG_HEAP_ALL_VISIBLE_CLEARED) {
+    if (xlrec->flags & XLH_INSERT_ALL_VISIBLE_CLEARED) {
         (*blocknum)++;
         XLogParseBufferAllocListFunc(record, &blockstate, recordstatehead);
         if (blockstate == NULL) {
diff --git a/src/gausskernel/storage/access/transam/cbmparsexlog.cpp b/src/gausskernel/storage/access/transam/cbmparsexlog.cpp
index 34271c7fd..aae05690e 100755
--- a/src/gausskernel/storage/access/transam/cbmparsexlog.cpp
+++ b/src/gausskernel/storage/access/transam/cbmparsexlog.cpp
@@ -1214,7 +1214,7 @@ static void TrackVMPageModification(XLogReaderState* record)
                     recData += sizeof(TransactionId);
                 xl_heap_insert* xlrec = (xl_heap_insert*)recData;
 
-                if (xlrec->flags & XLOG_HEAP_ALL_VISIBLE_CLEARED)
+                if (xlrec->flags & XLH_INSERT_ALL_VISIBLE_CLEARED)
                     (void)XLogRecGetBlockTag(record, 0, &rNode, NULL, &heapBlkNo1);
 
                 break;
@@ -1222,7 +1222,7 @@ static void TrackVMPageModification(XLogReaderState* record)
             case XLOG_HEAP_DELETE: {
                 xl_heap_delete* xlrec = (xl_heap_delete*)recData;
 
-                if (xlrec->flags & XLOG_HEAP_ALL_VISIBLE_CLEARED)
+                if (xlrec->flags & XLH_DELETE_ALL_VISIBLE_CLEARED)
                     (void)XLogRecGetBlockTag(record, 0, &rNode, NULL, &heapBlkNo1);
 
                 break;
@@ -1232,10 +1232,10 @@ static void TrackVMPageModification(XLogReaderState* record)
                     recData += sizeof(TransactionId);
                 xl_heap_update* xlrec = (xl_heap_update*)recData;
 
-                if (xlrec->flags & XLOG_HEAP_ALL_VISIBLE_CLEARED)
+                if (xlrec->flags & XLH_UPDATE_OLD_ALL_VISIBLE_CLEARED)
                     (void)XLogRecGetBlockTag(record, 1, &rNode, NULL, &heapBlkNo1);
 
-                if (xlrec->flags & XLOG_HEAP_ALL_VISIBLE_CLEARED)
+                if (xlrec->flags & XLH_UPDATE_OLD_ALL_VISIBLE_CLEARED)
                     (void)XLogRecGetBlockTag(record, 0, &rNode, NULL, &heapBlkNo2);
 
                 break;
@@ -1249,7 +1249,7 @@ static void TrackVMPageModification(XLogReaderState* record)
                 recData += sizeof(TransactionId);
             xl_heap_multi_insert* xlrec = (xl_heap_multi_insert*)recData;
 
-            if (xlrec->flags & XLOG_HEAP_ALL_VISIBLE_CLEARED)
+            if (xlrec->flags & XLH_INSERT_ALL_VISIBLE_CLEARED)
                 (void)XLogRecGetBlockTag(record, 0, &rNode, NULL, &heapBlkNo1);
         }
     } else
diff --git a/src/gausskernel/storage/replication/logical/decode.cpp b/src/gausskernel/storage/replication/logical/decode.cpp
index 7f8fceede..fe8889e8d 100644
--- a/src/gausskernel/storage/replication/logical/decode.cpp
+++ b/src/gausskernel/storage/replication/logical/decode.cpp
@@ -675,7 +675,7 @@ static void DecodeInsert(LogicalDecodingContext* ctx, XLogRecordBuffer* buf)
     rc = memcpy_s(&change->data.tp.relnode, sizeof(RelFileNode), &target_node, sizeof(RelFileNode));
     securec_check(rc, "\0", "\0");
 
-    if (xlrec->flags & XLOG_HEAP_CONTAINS_NEW_TUPLE) {
+    if (xlrec->flags & XLH_INSERT_CONTAINS_NEW_TUPLE) {
         change->data.tp.newtuple = ReorderBufferGetTupleBuf(ctx->reorder, tuplelen);
 
         DecodeXLogTuple(tupledata, tuplelen, change->data.tp.newtuple);
@@ -741,11 +741,11 @@ static void DecodeUpdate(LogicalDecodingContext* ctx, XLogRecordBuffer* buf)
     change->origin_id = XLogRecGetOrigin(r);
     rc = memcpy_s(&change->data.tp.relnode, sizeof(RelFileNode), &target_node, sizeof(RelFileNode));
     securec_check(rc, "", "");
-    if (xlrec->flags & XLOG_HEAP_CONTAINS_NEW_TUPLE) {
+    if (xlrec->flags & XLH_UPDATE_CONTAINS_NEW_TUPLE) {
         change->data.tp.newtuple = ReorderBufferGetTupleBuf(ctx->reorder, tuplelen_new);
         DecodeXLogTuple(data_new, datalen_new, change->data.tp.newtuple);
     }
-    if (xlrec->flags & XLOG_HEAP_CONTAINS_OLD) {
+    if (xlrec->flags & XLH_UPDATE_CONTAINS_OLD) {
         change->data.tp.oldtuple = ReorderBufferGetTupleBuf(ctx->reorder, tuplelen_old);
 
         DecodeXLogTuple(data_old, datalen_old, change->data.tp.oldtuple);
@@ -790,7 +790,7 @@ static void DecodeDelete(LogicalDecodingContext* ctx, XLogRecordBuffer* buf)
     securec_check(rc, "", "");
 
     /* old primary key stored */
-    if (xlrec->flags & XLOG_HEAP_CONTAINS_OLD) {
+    if (xlrec->flags & XLH_DELETE_CONTAINS_OLD) {
         Assert(XLogRecGetDataLen(r) > (SizeOfHeapDelete + SizeOfHeapHeader));
         change->data.tp.oldtuple = ReorderBufferGetTupleBuf(ctx->reorder, datalen);
 
@@ -848,7 +848,7 @@ static void DecodeMultiInsert(LogicalDecodingContext* ctx, XLogRecordBuffer* buf
          * We decode the tuple in pretty much the same way as DecodeXLogTuple,
          * but since the layout is slightly different, we can't use it here.
          */
-        if (xlrec->flags & XLOG_HEAP_CONTAINS_NEW_TUPLE) {
+        if (xlrec->flags & XLH_INSERT_CONTAINS_NEW_TUPLE) {
             HeapTupleHeader header;
             xlhdr = (xl_multi_insert_tuple*)data;
             data = ((char*)xlhdr) + SizeOfMultiInsertTuple;
@@ -889,7 +889,7 @@ static void DecodeMultiInsert(LogicalDecodingContext* ctx, XLogRecordBuffer* buf
          * xl_multi_insert_tuple record emitted by one heap_multi_insert()
          * call.
          */
-        if ((xlrec->flags & XLOG_HEAP_LAST_MULTI_INSERT) && ((i + 1) == xlrec->ntuples)) {
+        if ((xlrec->flags & XLH_INSERT_LAST_IN_MULTI) && ((i + 1) == xlrec->ntuples)) {
             change->data.tp.clear_toast_afterwards = true;
         } else {
             change->data.tp.clear_toast_afterwards = false;
diff --git a/src/include/access/heapam.h b/src/include/access/heapam.h
index 6f2f765e4..86b9bc49b 100644
--- a/src/include/access/heapam.h
+++ b/src/include/access/heapam.h
@@ -119,6 +119,7 @@ extern BulkInsertState GetBulkInsertState(void);
 extern void FreeBulkInsertState(BulkInsertState);
 
 extern Oid heap_insert(Relation relation, HeapTuple tup, CommandId cid, int options, BulkInsertState bistate);
+extern void heap_abort_speculative(Relation relation, HeapTuple tuple);
 extern bool heap_page_prepare_for_xid(
     Relation relation, Buffer buffer, TransactionId xid, bool multi, bool pageReplication = false);
 extern bool heap_change_xidbase_after_freeze(Relation relation, Buffer buffer);
@@ -127,18 +128,19 @@ extern bool rewrite_page_prepare_for_xid(Page page, TransactionId xid, bool mult
 extern int heap_multi_insert(Relation relation, Relation parent, HeapTuple* tuples, int ntuples, CommandId cid, int options,
     BulkInsertState bistate, HeapMultiInsertExtraArgs* args);
 extern HTSU_Result heap_delete(Relation relation, ItemPointer tid, ItemPointer ctid, TransactionId* update_xmax,
-    CommandId cid, Snapshot crosscheck, bool wait);
+    CommandId cid, Snapshot crosscheck, bool wait, bool allow_delete_self = false);
 extern HTSU_Result heap_update(Relation relation, Relation parentRelation, ItemPointer otid, HeapTuple newtup,
-    ItemPointer ctid, TransactionId* update_xmax, CommandId cid, Snapshot crosscheck, bool wait);
+    ItemPointer ctid, TransactionId* update_xmax, CommandId cid, Snapshot crosscheck,
+    bool wait, bool allow_update_self = false);
 extern HTSU_Result heap_lock_tuple(Relation relation, HeapTuple tuple, Buffer* buffer, ItemPointer ctid,
-    TransactionId* update_xmax, CommandId cid, LockTupleMode mode, bool nowait);
+    TransactionId* update_xmax, CommandId cid, LockTupleMode mode, bool nowait, bool allow_lock_self = false);
 
 extern void heap_inplace_update(Relation relation, HeapTuple tuple);
 extern bool heap_freeze_tuple(HeapTuple tuple, TransactionId cutoff_xid);
 extern bool heap_tuple_needs_freeze(HeapTuple tuple, TransactionId cutoff_xid, Buffer buf);
 
 extern Oid simple_heap_insert(Relation relation, HeapTuple tup);
-extern void simple_heap_delete(Relation relation, ItemPointer tid);
+extern void simple_heap_delete(Relation relation, ItemPointer tid, int options = 0);
 extern void simple_heap_update(Relation relation, ItemPointer otid, HeapTuple tup);
 
 extern void heap_markpos(HeapScanDesc scan);
diff --git a/src/include/access/htup.h b/src/include/access/htup.h
index 9083b26a9..fc8bf9a78 100755
--- a/src/include/access/htup.h
+++ b/src/include/access/htup.h
@@ -691,23 +691,47 @@ static inline TransactionId HeapTupleGetRawXmax(HeapTuple tup)
 #define XLOG_HEAP3_NEW_CID 0x00
 #define XLOG_HEAP3_REWRITE 0x10
 
+/* we used to put all xl_heap_* together, which made us run out of opcodes (quickly)
+ * when trying to add a DELETE_IS_SUPER operation. Thus we split the codes carefully
+ * for INSERT, UPDATE, DELETE individually. each has 8 bits available to use.
+ */
 /*
- * xl_heap_* ->flag values, 8 bits are available
+ * xl_heap_insert/xl_heap_multi_insert flag values, 8 bits are available
  */
 /* PD_ALL_VISIBLE was cleared */
-#define XLOG_HEAP_ALL_VISIBLE_CLEARED (1 << 0)
+#define XLH_INSERT_ALL_VISIBLE_CLEARED		   (1<<0)
+#define XLH_INSERT_CONTAINS_NEW_TUPLE		   (1<<4)
+#define XLH_INSERT_LAST_IN_MULTI               (1<<7)
+
+/*
+ * xl_heap_update flag values, 8 bits are available.
+*/
+/* PD_ALL_VISIBLE was cleared */
+#define XLH_UPDATE_OLD_ALL_VISIBLE_CLEARED	   (1<<0)
 /* PD_ALL_VISIBLE was cleared in the 2nd page */
-#define XLOG_HEAP_NEW_ALL_VISIBLE_CLEARED (1 << 1)
-#define XLOG_HEAP_CONTAINS_OLD_TUPLE (1 << 2)
-#define XLOG_HEAP_CONTAINS_OLD_KEY (1 << 3)
-#define XLOG_HEAP_CONTAINS_NEW_TUPLE (1 << 4)
-#define XLOG_HEAP_PREFIX_FROM_OLD (1 << 5)
-#define XLOG_HEAP_SUFFIX_FROM_OLD (1 << 6)
-/* last xl_heap_multi_insert record for one heap_multi_insert() call */
-#define XLOG_HEAP_LAST_MULTI_INSERT (1 << 7)
+#define XLH_UPDATE_NEW_ALL_VISIBLE_CLEARED	   (1<<1)
+#define XLH_UPDATE_CONTAINS_OLD_TUPLE		   (1<<2)
+#define XLH_UPDATE_CONTAINS_OLD_KEY			   (1<<3)
+#define XLH_UPDATE_CONTAINS_NEW_TUPLE		   (1<<4)
+#define XLH_UPDATE_PREFIX_FROM_OLD			   (1<<5)
+#define XLH_UPDATE_SUFFIX_FROM_OLD			   (1<<6)
 
 /* convenience macro for checking whether any form of old tuple was logged */
-#define XLOG_HEAP_CONTAINS_OLD (XLOG_HEAP_CONTAINS_OLD_TUPLE | XLOG_HEAP_CONTAINS_OLD_KEY)
+#define XLH_UPDATE_CONTAINS_OLD					   \
+    (XLH_UPDATE_CONTAINS_OLD_TUPLE | XLH_UPDATE_CONTAINS_OLD_KEY)
+
+/*
+* xl_heap_delete flag values, 8 bits are available.
+*/
+/* PD_ALL_VISIBLE was cleared */
+#define XLH_DELETE_ALL_VISIBLE_CLEARED		   (1<<0)
+#define XLH_DELETE_IS_SUPER                    (1<<1)
+#define XLH_DELETE_CONTAINS_OLD_TUPLE		   (1<<2)
+#define XLH_DELETE_CONTAINS_OLD_KEY			   (1<<3)
+
+/* convenience macro for checking whether any form of old tuple was logged */
+#define XLH_DELETE_CONTAINS_OLD					   \
+    (XLH_DELETE_CONTAINS_OLD_TUPLE | XLH_DELETE_CONTAINS_OLD_KEY)
 
 /* This is what we need to know about delete */
 typedef struct xl_heap_delete {
diff --git a/src/include/access/tuptoaster.h b/src/include/access/tuptoaster.h
index b6c4c745b..9a8edca2c 100644
--- a/src/include/access/tuptoaster.h
+++ b/src/include/access/tuptoaster.h
@@ -165,7 +165,7 @@ extern HeapTuple toast_insert_or_update(
  *	Called by heap_delete().
  * ----------
  */
-extern void toast_delete(Relation rel, HeapTuple oldtup);
+extern void toast_delete(Relation rel, HeapTuple oldtup, int options);
 
 /* ----------
  * heap_tuple_fetch_attr() -
diff --git a/src/include/catalog/index.h b/src/include/catalog/index.h
index c4de4f8b4..1ed6517a0 100755
--- a/src/include/catalog/index.h
+++ b/src/include/catalog/index.h
@@ -48,11 +48,15 @@ typedef enum
 #define REINDEX_CGIN_INDEX (1<<5)
 #define	REINDEX_ALL_INDEX   (REINDEX_BTREE_INDEX|REINDEX_HASH_INDEX|REINDEX_GIN_INDEX|REINDEX_GIST_INDEX|REINDEX_CGIN_INDEX)
 
+typedef enum CheckWaitMode
+{
+    CHECK_WAIT,
+    CHECK_NOWAIT,
+} CheckWaitMode;
 
 extern void index_check_primary_key(Relation heapRel, IndexInfo *indexInfo, bool is_alter_table);
 
-typedef struct
-{
+typedef struct {
     Oid  existingPSortOid;
     bool isPartitionedIndex;
 } IndexCreateExtraArgs;
@@ -74,6 +78,8 @@ extern void index_drop(Oid indexId, bool concurrent);
 extern IndexInfo *BuildIndexInfo(Relation index);
 extern IndexInfo *BuildDummyIndexInfo(Relation index);
 
+extern void BuildSpeculativeIndexInfo(Relation index, IndexInfo* ii);
+
 extern void FormIndexDatum(IndexInfo *indexInfo, TupleTableSlot *slot, EState *estate, Datum *values, bool *isnull);
 extern void index_build(Relation heapRelation, Partition heapPartition, Relation indexRelation,
                         Partition indexPartition, IndexInfo *indexInfo, bool isprimary,
diff --git a/src/include/executor/executor.h b/src/include/executor/executor.h
index d3d16347c..e329385e0 100755
--- a/src/include/executor/executor.h
+++ b/src/include/executor/executor.h
@@ -367,13 +367,15 @@ extern void ExecCloseScanRelation(Relation scanrel);
 extern Partition ExecOpenScanParitition(
     EState* estate, Relation parent, PartitionIdentifier* partID, LOCKMODE lockmode);
 
-extern void ExecOpenIndices(ResultRelInfo* resultRelInfo);
+extern void ExecOpenIndices(ResultRelInfo* resultRelInfo, bool speculative);
 extern void ExecCloseIndices(ResultRelInfo* resultRelInfo);
 extern List* ExecInsertIndexTuples(
-    TupleTableSlot* slot, ItemPointer tupleid, EState* estate, Relation targetPartRel, Partition p, int2 bucketId);
+    TupleTableSlot* slot, ItemPointer tupleid, EState* estate, Relation targetPartRel,
+    Partition p, int2 bucketId, bool* conflict);
+extern bool ExecCheckIndexConstraints(TupleTableSlot* slot, EState* estate,
+    Relation targetRel, Partition p, int2 bucketId, ItemPointer conflictTid);
 extern bool check_exclusion_constraint(Relation heap, Relation index, IndexInfo* indexInfo, ItemPointer tupleid,
     Datum* values, const bool* isnull, EState* estate, bool newIndex, bool errorOK);
-
 extern void RegisterExprContextCallback(ExprContext* econtext, ExprContextCallbackFunction function, Datum arg);
 extern void UnregisterExprContextCallback(ExprContext* econtext, ExprContextCallbackFunction function, Datum arg);
 extern List* GetAccessedVarnoList(List* targetList, List* qual);
diff --git a/src/include/knl/knl_guc/knl_session_attr_sql.h b/src/include/knl/knl_guc/knl_session_attr_sql.h
index e3c7a2102..6527cc665 100644
--- a/src/include/knl/knl_guc/knl_session_attr_sql.h
+++ b/src/include/knl/knl_guc/knl_session_attr_sql.h
@@ -53,6 +53,7 @@ typedef struct knl_session_attr_sql {
     bool enable_sonic_optspill;
     bool enable_sonic_hashjoin;
     bool enable_sonic_hashagg;
+    bool enable_upsert_to_merge;
     bool enable_csqual_pushdown;
     bool enable_change_hjcost;
     bool enable_seqscan;
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 11c8ab5d6..b474775dd 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -61,6 +61,9 @@ typedef struct UtilityDesc {
  *		ExclusionOps		Per-column exclusion operators, or NULL if none
  *		ExclusionProcs		Underlying function OIDs for ExclusionOps
  *		ExclusionStrats		Opclass strategy numbers for ExclusionOps
+ *		UniqueOps           Theses are like Exclusion*, but for unique indexes
+ *		UniqueProcs
+ *		UniqueStrats
  *		Unique				is it a unique index?
  *		ReadyForInserts		is it valid for inserts?
  *		Concurrent			are we doing a concurrent index build?
@@ -81,6 +84,9 @@ typedef struct IndexInfo {
     Oid* ii_ExclusionOps;       /* array with one entry per column */
     Oid* ii_ExclusionProcs;     /* array with one entry per column */
     uint16* ii_ExclusionStrats; /* array with one entry per column */
+    Oid *ii_UniqueOps;          /* array with one entry per column */
+    Oid *ii_UniqueProcs;        /* array with one entry per column */
+    uint16 *ii_UniqueStrats;    /* array with one entry per column */
     bool ii_Unique;
     bool ii_ReadyForInserts;
     bool ii_Concurrent;
@@ -396,6 +402,7 @@ typedef struct MergeState {
  *		ConstraintExprs			array of constraint-checking expr states
  *		junkFilter				for removing junk attributes from tuples
  *		projectReturning		for computing a RETURNING list
+ *		updateProj				for computing a UPSERT update list
  * ----------------
  */
 typedef struct ResultRelInfo {
@@ -434,6 +441,7 @@ typedef struct ResultRelInfo {
      * ri_RangeTableIndex elsewhere.
      */
     Index ri_mergeTargetRTI;
+    ProjectionInfo* ri_updateProj;
 } ResultRelInfo;
 
 /* bloom filter controller */
@@ -1292,6 +1300,18 @@ typedef struct MergeActionState {
     VectorBatch* scanBatch; /* scan batch for UPDATE */
 } MergeActionState;
 
+/* ----------------
+ *	 UpsertState information
+ * ----------------
+ */
+typedef struct UpsertState {
+	NodeTag			type;
+	UpsertAction	us_action;                  /* Flags showing DUPLICATE UPDATE NOTHING or SOMETHING */
+	TupleTableSlot* us_existing;                /* slot to store existing target tuple in */
+	List*           us_excludedtlist;           /* the excluded pseudo relation's tlist */
+	TupleTableSlot* us_updateproj;              /* slot to update */
+} UpsertState;
+
 /* ----------------
  *	 ModifyTableState information
  * ----------------
@@ -1326,7 +1346,7 @@ typedef struct ModifyTableState {
     TupleTableSlot* mt_insert_constr_slot; /* slot to store target tuple in for checking constraints */
     TupleTableSlot* mt_mergeproj;          /* MERGE action projection target */
     uint32 mt_merge_subcommands;           /* Flags showing which subcommands are present INS/UPD/DEL/DO NOTHING */
-
+    UpsertState* mt_upsert;                /*  DUPLICATE KEY UPDATE evaluation state */
     instr_time first_tuple_modified; /* record the end time for the first tuple inserted, deleted, or updated */
 } ModifyTableState;
 
diff --git a/src/include/nodes/nodes.h b/src/include/nodes/nodes.h
index 1f5398918..1c900fe0d 100644
--- a/src/include/nodes/nodes.h
+++ b/src/include/nodes/nodes.h
@@ -210,6 +210,7 @@ typedef enum NodeTag {
     T_RangeTblRef,
     T_JoinExpr,
     T_FromExpr,
+	T_UpsertExpr,
     T_IntoClause,
     T_IndexVar,
 #ifdef PGXC
@@ -304,7 +305,7 @@ typedef enum NodeTag {
 #endif /* PGXC */
     T_StreamPath,
     T_MergeAction,
-
+	T_UpsertState,
     /*
      * TAGS FOR MEMORY NODES (memnodes.h)
      */
@@ -499,7 +500,7 @@ typedef enum NodeTag {
     T_PruningResult,
     T_Position,
     T_MergeWhenClause,
-
+	T_UpsertClause,
     /*
      * TAGS FOR REPLICATION GRAMMAR PARSE NODES (replnodes.h)
      */
@@ -894,4 +895,10 @@ typedef enum JoinType {
                               (1 << JOIN_RIGHT_ANTI) | (1 << JOIN_LEFT_ANTI_FULL) | (1 << JOIN_RIGHT_ANTI_FULL))) != \
         0)
 
+typedef enum UpsertAction {
+    UPSERT_NONE,            /* No "DUPLICATE KEY UPDATE" clause */
+    UPSERT_NOTHING,         /* DUPLICATE KEY UPDATE NOTHING */
+    UPSERT_UPDATE           /* DUPLICATE KEY UPDATE ... */
+}UpsertAction;
+
 #endif /* NODES_H */
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 78d9f6db4..dd3dc1c5b 100755
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -234,6 +234,7 @@ typedef struct Query {
     List* mergeSourceTargetList;
     List* mergeActionList; /* list of actions for MERGE (only) */
     Query* upsertQuery;    /* insert query for INSERT ON DUPLICATE KEY UPDATE (only) */
+    UpsertExpr* upsertClause; /* DUPLICATE KEY UPDATE [NOTHING | ...] */
 
     bool isRowTriggerShippable; /* true if all row triggers are shippable. */
     bool use_star_targets;      /* true if use * for targetlist. */
@@ -942,6 +943,8 @@ typedef struct RangeTblEntry {
     bool relhasbucket; /* the rel has underlying buckets, get from pg_class */
     bool isbucket;	  /* the sql only want some buckets from the rel */
     List* buckets;	  /* the bucket id wanted */
+
+    bool isexcluded; /* the rel is the EXCLUDED relation for UPSERT */
 } RangeTblEntry;
 
 /*
@@ -1139,6 +1142,13 @@ typedef struct WithClause {
     int location;   /* token location, or -1 if unknown */
 } WithClause;
 
+typedef struct UpsertClause
+{
+    NodeTag type;
+    List* targetList;
+    int location;
+} UpsertClause;
+
 /*
  * CommonTableExpr -
  *	   representation of WITH list element
@@ -1194,6 +1204,7 @@ typedef struct InsertStmt {
     Node* selectStmt;       /* the source SELECT/VALUES, or NULL */
     List* returningList;    /* list of expressions to return */
     WithClause* withClause; /* WITH clause */
+    UpsertClause* upsertClause;  /* DUPLICATE KEY UPDATE clause */
 } InsertStmt;
 
 /* ----------------------
diff --git a/src/include/nodes/plannodes.h b/src/include/nodes/plannodes.h
index 6c6efc089..f62ecc5aa 100755
--- a/src/include/nodes/plannodes.h
+++ b/src/include/nodes/plannodes.h
@@ -412,7 +412,13 @@ typedef struct ModifyTable {
     Index mergeTargetRelation; /* RT index of the merge target */
     List* mergeSourceTargetList;
     List* mergeActionList; /* actions for MERGE */
-    OpMemInfo mem_info;    /*  Memory info for modify node */
+
+    UpsertAction upsertAction; /* DUPLICATE KEY UPDATE action */
+    List* updateTlist;         /* List of UPDATE target */
+    List* exclRelTlist;        /* target list of the EXECLUDED pseudo relation */
+    Index exclRelRTIndex;      /* RTI of the EXCLUDED pseudo relation */
+
+    OpMemInfo mem_info;    /* Memory info for modify node */
 } ModifyTable;
 
 /* ----------------
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index c161e16a2..d7000a823 100755
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -1359,4 +1359,14 @@ typedef struct {
     bool indexpath;
 } IndexVar;
 
+typedef struct UpsertExpr {
+    NodeTag type;
+    UpsertAction upsertAction;    /* DO NOTHING or UPDATE? */
+
+    /* DUPLICATE KEY UPDATE */
+    List* updateTlist;        /* List of UPDATE TargetEntrys */
+    List* exclRelTlist;       /* tlist of the 'EXCLUDED' pseudo relation */
+    int exclRelIndex;        /* RT index of 'EXCLUDED' relation */
+} UpsertExpr;
+
 #endif /* PRIMNODES_H */
diff --git a/src/include/opfusion/opfusion_util.h b/src/include/opfusion/opfusion_util.h
index f6aedc13c..97b15e376 100644
--- a/src/include/opfusion/opfusion_util.h
+++ b/src/include/opfusion/opfusion_util.h
@@ -64,6 +64,7 @@ enum FusionType {
     NOBYPASS_INVALID_SELECT_FOR_UPDATE,
     NOBYPASS_INVALID_MODIFYTABLE,
     NOBYPASS_NO_SIMPLE_INSERT,
+    NOBYPASS_UPSERT_NOT_SUPPORT,
 
     NOBYPASS_NO_INDEXSCAN,
     NOBYPASS_INDEXSCAN_WITH_ORDERBY,
diff --git a/src/include/optimizer/planmain.h b/src/include/optimizer/planmain.h
index 2b04b226e..2c6cf7133 100755
--- a/src/include/optimizer/planmain.h
+++ b/src/include/optimizer/planmain.h
@@ -109,21 +109,21 @@ extern int get_plan_actual_total_width(Plan* plan, bool vectorized, OpType type,
 #ifdef STREAMPLAN
 extern Plan* make_modifytable(PlannerInfo* root, CmdType operation, bool canSetTag, List* resultRelations,
     List* subplans, List* returningLists, List* rowMarks, int epqParam, bool partKeyUpdated, Index mergeTargetRelation,
-    List* mergeSourceTargetList, List* mergeActionList, bool isDfsStore = false);
+    List* mergeSourceTargetList, List* mergeActionList, UpsertExpr* upsertClause, bool isDfsStore = false);
 extern Plan* make_modifytables(PlannerInfo* root, CmdType operation, bool canSetTag, List* resultRelations,
     List* subplans, List* returningLists, List* rowMarks, int epqParam, bool partKeyUpdated, bool isDfsStore,
-    Index mergeTargetRelation, List* mergeSourceTargetList, List* mergeActionList);
+    Index mergeTargetRelation, List* mergeSourceTargetList, List *mergeActionList, UpsertExpr *upsertClause);
 extern Plan* make_redistribute_for_agg(PlannerInfo* root, Plan* lefttree, List* redistribute_keys, double multiple,
     Distribution* distribution = NULL, bool is_local_redistribute = false);
 extern Plan* make_stream_plan(PlannerInfo* root, Plan* lefttree, List* redistribute_keys, double multiple,
     Distribution* target_distribution = NULL);
 #else
-extern ModifyTable* make_modifytable(CmdType operation, bool canSetTag, List* resultRelations, List* subplans,
-    List* returningLists, List* rowMarks, int epqParam, bool partKeyUpdated, Index mergeTargetRelation,
-    List* mergeSourceTargetList, List* mergeActionList, bool isDfsStore = false);
-extern ModifyTable* make_modifytables(CmdType operation, bool canSetTag, List* resultRelations, List* subplans,
-    List* returningLists, List* rowMarks, int epqParam, bool partKeyUpdated, bool isDfsStore, Index mergeTargetRelation,
-    List* mergeSourceTargetList, List* mergeActionList);
+extern ModifyTable* make_modifytable(CmdType operation, bool canSetTag, List* resultRelations,
+    List* subplans, List* returningLists, List* rowMarks, int epqParam, bool partKeyUpdated, Index mergeTargetRelation,
+    List* mergeSourceTargetList, List* mergeActionList, UpsertExpr* upsertClause, bool isDfsStore = false);
+extern ModifyTable* make_modifytables(CmdType operation, bool canSetTag, List* resultRelations,
+    List* subplans, List* returningLists, List* rowMarks, int epqParam, bool partKeyUpdated, bool isDfsStore,
+    Index mergeTargetRelation, List* mergeSourceTargetList, List* mergeActionList, UpsertExpr* upsertClause);
 #endif
 
 extern bool is_projection_capable_plan(Plan* plan);
diff --git a/src/include/optimizer/prep.h b/src/include/optimizer/prep.h
index 5ab906e72..8e3cb4009 100755
--- a/src/include/optimizer/prep.h
+++ b/src/include/optimizer/prep.h
@@ -58,7 +58,7 @@ extern Expr* canonicalize_qual(Expr* qual);
  * prototypes for preptlist.c
  */
 extern List* preprocess_targetlist(PlannerInfo* root, List* tlist);
-
+extern List* preprocess_upsert_targetlist(List* tlist, int result_relation, List* range_table);
 extern PlanRowMark* get_plan_rowmark(List* rowmarks, Index rtindex);
 
 /*
diff --git a/src/include/parser/parse_merge.h b/src/include/parser/parse_merge.h
index ff0c2a603..6074e1dac 100755
--- a/src/include/parser/parse_merge.h
+++ b/src/include/parser/parse_merge.h
@@ -19,4 +19,5 @@ extern Query* transformMergeStmt(ParseState* pstate, MergeStmt* stmt);
 extern List* expandTargetTL(List* te_list, Query* parsetree);
 extern List* expandActionTL(List* te_list, Query* parsetree);
 extern List* expandQualTL(List* te_list, Query* parsetree);
+extern bool check_unique_constraint(List*& index_list);
 #endif
diff --git a/src/include/parser/parse_node.h b/src/include/parser/parse_node.h
index 24fc85669..2b349b37c 100755
--- a/src/include/parser/parse_node.h
+++ b/src/include/parser/parse_node.h
@@ -106,7 +106,6 @@ struct ParseState {
     bool p_hasSubLinks;
     bool p_hasModifyingCTE;
     bool p_is_insert;
-    bool p_is_update;
     bool p_locked_from_parent;
     bool p_resolve_unknowns; /* resolve unknown-type SELECT outputs as type text */
     bool p_hasSynonyms;
diff --git a/src/include/parser/parse_relation.h b/src/include/parser/parse_relation.h
index 7db2ffa4e..5f5f8b0bc 100755
--- a/src/include/parser/parse_relation.h
+++ b/src/include/parser/parse_relation.h
@@ -23,7 +23,7 @@ extern void checkNameSpaceConflicts(ParseState* pstate, List* namespace1, List*
 extern int RTERangeTablePosn(ParseState* pstate, RangeTblEntry* rte, int* sublevels_up);
 extern RangeTblEntry* GetRTEByRangeTablePosn(ParseState* pstate, int varno, int sublevels_up);
 extern CommonTableExpr* GetCTEForRTE(ParseState* pstate, RangeTblEntry* rte, int rtelevelsup);
-extern Node* scanRTEForColumn(ParseState* pstate, RangeTblEntry* rte, char* colname, int location);
+extern Node* scanRTEForColumn(ParseState* pstate, RangeTblEntry* rte, char* colname, int location, bool omit = false);
 extern Node* colNameToVar(
     ParseState* pstate, char* colname, bool localonly, int location, RangeTblEntry** final_rte = NULL);
 extern void markVarForSelectPriv(ParseState* pstate, Var* var, RangeTblEntry* rte);
diff --git a/src/include/utils/snapshot.h b/src/include/utils/snapshot.h
index 7c77d74fc..242244d28 100755
--- a/src/include/utils/snapshot.h
+++ b/src/include/utils/snapshot.h
@@ -120,7 +120,8 @@ typedef enum {
     HeapTupleInvisible,
     HeapTupleSelfUpdated,
     HeapTupleUpdated,
-    HeapTupleBeingUpdated
+    HeapTupleBeingUpdated,
+    HeapTupleSelfCreated
 } HTSU_Result;
 
 #endif /* SNAPSHOT_H */
diff --git a/src/include/utils/tqual.h b/src/include/utils/tqual.h
index 54193c60f..94a757865 100755
--- a/src/include/utils/tqual.h
+++ b/src/include/utils/tqual.h
@@ -70,7 +70,7 @@ extern bool HeapTupleSatisfiesToast(HeapTuple htup, Snapshot snapshot, Buffer bu
 extern bool HeapTupleSatisfiesDirty(HeapTuple htup, Snapshot snapshot, Buffer buffer);
 extern bool HeapTupleSatisfiesHistoricMVCC(HeapTuple htup, Snapshot snapshot, Buffer buffer);
 /* Special "satisfies" routines with different APIs */
-extern HTSU_Result HeapTupleSatisfiesUpdate(HeapTuple htup, CommandId curcid, Buffer buffer);
+extern HTSU_Result HeapTupleSatisfiesUpdate(HeapTuple htup, CommandId curcid, Buffer buffer, bool self_visible = false);
 extern HTSV_Result HeapTupleSatisfiesVacuum(HeapTuple htup, TransactionId OldestXmin, Buffer buffer);
 extern bool HeapTupleIsSurelyDead(HeapTuple htup, TransactionId OldestXmin);
 
diff --git a/src/test/regress/expected/upsert_explain.out b/src/test/regress/expected/upsert_explain.out
index 5ff2ec4d1..0efb8cbea 100644
--- a/src/test/regress/expected/upsert_explain.out
+++ b/src/test/regress/expected/upsert_explain.out
@@ -295,3 +295,4 @@ EXPLAIN (ANALYZE on, COSTS off, TIMING off)  insert into up_expl_node values(1,1
    ->  Result (actual rows=1 loops=1)
 --? Total runtime: .* ms
 (5 rows)
+