1. Incorrect behavior in update/delete queries with repeating access to same records

2.     Change MOT key operator for expr with l-values

src/gausskernel/storage/mot/core/src/system/transaction/txn.cpp

@@ -137,6 +137,7 @@ RC TxnManager::DeleteLastRow()
     rc = m_accessMgr->UpdateRowState(AccessType::DEL, access);
     if (rc != RC_OK)
         return rc;
+    access->m_stmtCount = GetStmtCount();
     return rc;
 }
 
@@ -145,6 +146,18 @@ RC TxnManager::UpdateLastRowState(AccessType state)
     return m_accessMgr->UpdateRowState(state, m_accessMgr->GetLastAccess());
 }
 
+bool TxnManager::IsUpdatedInCurrStmt()
+{
+    Access* access = m_accessMgr->GetLastAccess();
+    if (access == nullptr) {
+        return false;
+    }
+    if (m_internalStmtCount == m_accessMgr->GetLastAccess()->m_stmtCount) {
+        return true;
+    }
+    return false;
+}
+
 RC TxnManager::StartTransaction(uint64_t transactionId, int isolationLevel)
 {
     m_transactionId = transactionId;
@@ -781,8 +794,10 @@ RC TxnManager::OverwriteRow(Row* updatedRow, BitmapSet& modifiedColumns)
         return RC_ERROR;
 
     Access* access = m_accessMgr->GetLastAccess();
-    if (access->m_type == AccessType::WR)
+    if (access->m_type == AccessType::WR) {
         access->m_modifiedColumns |= modifiedColumns;
+        access->m_stmtCount = GetStmtCount();
+    }
     return RC_OK;
 }
 

src/gausskernel/storage/mot/core/src/system/transaction/txn.h

@@ -471,6 +471,8 @@ public:
         m_occManager.SetValidationNoWait(b);
     }
 
+    bool IsUpdatedInCurrStmt();
+
 private:
     static constexpr uint32_t SESSION_ID_BITS = 32;
 

src/gausskernel/storage/mot/fdw_adapter/src/mot_fdw.cpp

@@ -1508,6 +1508,10 @@ static TupleTableSlot* MOTExecForeignUpdate(
         return nullptr;
     }
 
+    // This case handle multiple updates of the same row in one query
+    if (fdwState->m_currTxn->IsUpdatedInCurrStmt()) {
+        return nullptr;
+    }
     if ((rc = MOTAdaptor::UpdateRow(fdwState, planSlot, currRow)) == MOT::RC_OK) {
         if (resultRelInfo->ri_projectReturning) {
             return planSlot;
@@ -1552,6 +1556,10 @@ static TupleTableSlot* MOTExecForeignDelete(
     }
 
     if (currRow == nullptr) {
+        // This case handle multiple updates of the same row in one query
+        if (fdwState->m_currTxn->IsUpdatedInCurrStmt()) {
+            return nullptr;
+        }
         elog(ERROR, "MOTExecForeignDelete failed to fetch row");
         CleanQueryStatesOnError(fdwState->m_currTxn);
         report_pg_error(((rc == MOT::RC_OK) ? MOT::RC_ERROR : rc), fdwState->m_currTxn);
@@ -2233,6 +2241,20 @@ inline bool IsNotEqualOper(OpExpr* op)
     }
 }
 
+inline void RevertKeyOperation(KEY_OPER& oper)
+{
+    if (oper == KEY_OPER::READ_KEY_BEFORE) {
+        oper = KEY_OPER::READ_KEY_AFTER;
+    } else if (oper == KEY_OPER::READ_KEY_OR_PREV) {
+        oper = KEY_OPER::READ_KEY_OR_NEXT;
+    } else if (oper == KEY_OPER::READ_KEY_AFTER) {
+        oper = KEY_OPER::READ_KEY_BEFORE;
+    } else if (oper == KEY_OPER::READ_KEY_OR_NEXT) {
+        oper = KEY_OPER::READ_KEY_OR_PREV;
+    }
+    return;
+}
+
 inline bool GetKeyOperation(OpExpr* op, KEY_OPER& oper)
 {
     switch (op->opno) {
@@ -2411,11 +2433,13 @@ bool IsMOTExpr(RelOptInfo* baserel, MOTFdwStateSt* state, MatchIndexArr* marr, E
                         } else {
                             v = (Var*)r;
                             e = l;
+                            RevertKeyOperation(oper);
                         }
                     }
                 } else if (IsA(r, Var)) {
                     v = (Var*)r;
                     e = l;
+                    RevertKeyOperation(oper);
                 } else {
                     isOperatorMOTReady = false;
                     break;

src/test/regress/expected/mot/single_float8.out

@@ -167,8 +167,10 @@ SELECT '' AS one, f.* FROM FLOAT8_TBL f WHERE f.f1 = '1004.3';
 SELECT '' AS three, f.* FROM FLOAT8_TBL f WHERE '1004.3' > f.f1 ORDER BY f1;
  three |          f1          
 -------+----------------------
-       | 1.2345678901234e+200
-(1 row)
+       |               -34.84
+       |                    0
+       | 1.2345678901234e-200
+(3 rows)
 
 SELECT '' AS three, f.* FROM FLOAT8_TBL f WHERE  f.f1 < '1004.3' ORDER BY f1;
  three |          f1          
@@ -181,9 +183,11 @@ SELECT '' AS three, f.* FROM FLOAT8_TBL f WHERE  f.f1 < '1004.3' ORDER BY f1;
 SELECT '' AS four, f.* FROM FLOAT8_TBL f WHERE '1004.3' >= f.f1 ORDER BY f1;
  four |          f1          
 ------+----------------------
+      |               -34.84
+      |                    0
+      | 1.2345678901234e-200
       |               1004.3
-      | 1.2345678901234e+200
-(2 rows)
+(4 rows)
 
 SELECT '' AS four, f.* FROM FLOAT8_TBL f WHERE  f.f1 <= '1004.3' ORDER BY f1;
  four |          f1