diff --git a/source/dnode/mnode/impl/src/mndStb.c b/source/dnode/mnode/impl/src/mndStb.c
index 2a369a863a8f6a79356d058992c0717d16c2a557..9e613648016f4c01f39da34f3663f2a3c69a962a 100644
--- a/source/dnode/mnode/impl/src/mndStb.c
+++ b/source/dnode/mnode/impl/src/mndStb.c
@@ -3114,6 +3114,7 @@ static int32_t mndRetrieveStbCol(SRpcMsg *pReq, SShowObj *pShow, SSDataBlock *pB
   char typeName[TSDB_TABLE_FNAME_LEN + VARSTR_HEADER_SIZE] = {0};
   STR_TO_VARSTR(typeName, "SUPER_TABLE");
   while (numOfRows < rows) {
+    void *prevIter = pShow->pIter;
     pShow->pIter = sdbFetch(pSdb, SDB_STB, pShow->pIter, (void **)&pStb);
     if (pShow->pIter == NULL) break;
 
@@ -3122,6 +3123,12 @@ static int32_t mndRetrieveStbCol(SRpcMsg *pReq, SShowObj *pShow, SSDataBlock *pB
       continue;
     }
 
+    if ((numOfRows + pStb->numOfColumns) > rows) {
+      pShow->pIter = prevIter;
+      sdbRelease(pSdb, pStb);
+      break;
+    }
+
     SName name = {0};
     char  stbName[TSDB_TABLE_NAME_LEN + VARSTR_HEADER_SIZE] = {0};
     mndExtractTbNameFromStbFullName(pStb->name, &stbName[VARSTR_HEADER_SIZE], TSDB_TABLE_NAME_LEN);
diff --git a/source/libs/executor/src/sysscanoperator.c b/source/libs/executor/src/sysscanoperator.c
index 38c1d60899e2a61239a4464013e4bb3bde0433b7..20766b38d63e5d3da59529fc02bb9b84a46d38da 100644
--- a/source/libs/executor/src/sysscanoperator.c
+++ b/source/libs/executor/src/sysscanoperator.c
@@ -436,7 +436,7 @@ static SSDataBlock* sysTableScanUserCols(SOperatorInfo* pOperator) {
   int32_t numOfRows = 0;
 
   SSDataBlock* dataBlock = buildInfoSchemaTableMetaBlock(TSDB_INS_TABLE_COLS);
-  blockDataEnsureCapacity(dataBlock, pOperator->resultInfo.capacity + TSDB_MAX_COLUMNS);
+  blockDataEnsureCapacity(dataBlock, pOperator->resultInfo.capacity);
 
   const char* db = NULL;
   int32_t     vgId = 0;