diff --git a/src/common/backend/nodes/nodeFuncs.cpp b/src/common/backend/nodes/nodeFuncs.cpp
index 7602b28c4..df2188520 100644
--- a/src/common/backend/nodes/nodeFuncs.cpp
+++ b/src/common/backend/nodes/nodeFuncs.cpp
@@ -235,6 +235,12 @@ Oid exprType(const Node* expr)
         case T_SetVariableExpr:
             type = ((const Const*)(((SetVariableExpr*)expr)->value))->consttype;
             break;
+        case T_UserSetElem:
+            ereport(ERROR,
+                (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+                errmsg("user_defined variables cannot be set, such as @var_name := expr is not supported.")));
+            type = InvalidOid; /* keep compiler quiet */
+            break;
         default:
             ereport(ERROR,
                 (errcode(ERRCODE_UNRECOGNIZED_NODE_TYPE), errmsg("unrecognized node type: %d", (int)nodeTag(expr))));
@@ -863,6 +869,12 @@ Oid exprCollation(const Node* expr)
         case T_SetVariableExpr:
             coll = ((const Const*)(((SetVariableExpr*)expr)->value))->constcollid;
             break;
+        case T_UserSetElem:
+            ereport(ERROR,
+                (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+                errmsg("user_defined variables cannot be set, such as @var_name := expr is not supported.")));
+            coll = InvalidOid; /* keep compiler quiet */
+            break;
         default:
             ereport(
                 ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("unrecognized node type: %d", (int)nodeTag(expr))));
@@ -1068,6 +1080,11 @@ void exprSetCollation(Node* expr, Oid collation)
         case T_SetVariableExpr:
             ((Const*)(((SetVariableExpr*)expr)->value))->constcollid = collation;
             break;
+        case T_UserSetElem:
+            ereport(ERROR,
+                (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+                errmsg("user_defined variables cannot be set, such as @var_name := expr is not supported.")));
+            break;
         default:
             ereport(
                 ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("unrecognized node type: %d", (int)nodeTag(expr))));
@@ -1906,6 +1923,11 @@ bool expression_tree_walker(Node* node, bool (*walker)(), void* context)
             return p2walker(((AutoIncrement*)node)->expr, context);
         case T_PrefixKey:
             return p2walker(((PrefixKey*)node)->arg, context);
+        case T_UserSetElem:
+            ereport(ERROR,
+                (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+                errmsg("user_defined variables cannot be set, such as @var_name := expr is not supported.")));
+            break;
         default:
             ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH),
                             errmsg("expression_tree_walker:unrecognized node type: %d", (int)nodeTag(node))));
@@ -2654,6 +2676,11 @@ Node* expression_tree_mutator(Node* node, Node* (*mutator)(Node*, void*), void*
             MUTATE(newnode->value, oldnode->value, Expr*);
             return (Node*)newnode;
         } break;
+        case T_UserSetElem:
+            ereport(ERROR,
+                (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+                errmsg("user_defined variables cannot be set, such as @var_name := expr is not supported.")));
+            break;
         default:
             ereport(ERROR,
                 (errcode(ERRCODE_UNRECOGNIZED_NODE_TYPE), errmsg("unrecognized node type: %d", (int)nodeTag(node))));
diff --git a/src/common/backend/utils/misc/guc.cpp b/src/common/backend/utils/misc/guc.cpp
index 90c7325fb..bf5617eeb 100755
--- a/src/common/backend/utils/misc/guc.cpp
+++ b/src/common/backend/utils/misc/guc.cpp
@@ -1085,7 +1085,7 @@ static void InitConfigureNamesBool()
             NULL},
 #endif
         {{"enable_set_variable_b_format",
-            PGC_SIGHUP,
+            PGC_USERSET,
             NODE_ALL,
             INSTRUMENTS_OPTIONS,
             gettext_noop("enable set variable in b format."),
diff --git a/src/test/regress/input/set_user_defined_variables_test.source b/src/test/regress/input/set_user_defined_variables_test.source
index 2538c1905..b89d1cf1d 100644
--- a/src/test/regress/input/set_user_defined_variables_test.source
+++ b/src/test/regress/input/set_user_defined_variables_test.source
@@ -467,6 +467,17 @@ select @v1;
 set @ v1:=10;
 select @v1:=10;
 
+\c test_set
+show enable_set_variable_b_format;
+set enable_set_variable_b_format = off;
+set @v1 := 1, @v2 := 2, @v3 := @v4 := 3;
+
+\c test_set
+show enable_set_variable_b_format;
+set enable_set_variable_b_format = on;
+set @v1 := 1, @v2 := 2, @v3 := @v4 := 3;
+select @v1, @v2, @v3, @v4;
+
 \c regression
 drop database if exists test_set;
 
diff --git a/src/test/regress/output/set_user_defined_variables_test.source b/src/test/regress/output/set_user_defined_variables_test.source
index d1d1f08fe..5273b575a 100644
--- a/src/test/regress/output/set_user_defined_variables_test.source
+++ b/src/test/regress/output/set_user_defined_variables_test.source
@@ -1004,7 +1004,34 @@ ERROR:  syntax error at or near "@"
 LINE 1: set @ v1:=10;
             ^
 select @v1:=10;
-ERROR:  unrecognized node type: 5014
+ERROR:  user_defined variables cannot be set, such as @var_name := expr is not supported.
+\c test_set
+show enable_set_variable_b_format;
+ enable_set_variable_b_format 
+------------------------------
+ on
+(1 row)
+
+set enable_set_variable_b_format = off;
+set @v1 := 1, @v2 := 2, @v3 := @v4 := 3;
+ERROR:  syntax error at or near "set @"
+LINE 1: set @v1 := 1, @v2 := 2, @v3 := @v4 := 3;
+        ^
+\c test_set
+show enable_set_variable_b_format;
+ enable_set_variable_b_format 
+------------------------------
+ on
+(1 row)
+
+set enable_set_variable_b_format = on;
+set @v1 := 1, @v2 := 2, @v3 := @v4 := 3;
+select @v1, @v2, @v3, @v4;
+ @v1 | @v2 | @v3 | @v4 
+-----+-----+-----+-----
+   1 |   2 |   3 |   3
+(1 row)
+
 \c regression
 drop database if exists test_set;
 \! @abs_bindir@/gs_guc reload -Z datanode -D @abs_srcdir@/tmp_check/datanode1 -c "enable_set_variable_b_format=off" >/dev/null 2>&1