diff --git a/source/libs/executor/src/sysscanoperator.c b/source/libs/executor/src/sysscanoperator.c
index fd766e21f81595af7969a924493ade90011b8205..19c65e62cc5b9a52bef3acb350553734016284ac 100644
--- a/source/libs/executor/src/sysscanoperator.c
+++ b/source/libs/executor/src/sysscanoperator.c
@@ -1593,6 +1593,8 @@ static SSDataBlock* doSysTableScan(SOperatorInfo* pOperator) {
   SSysTableScanInfo* pInfo = pOperator->info;
   char               dbName[TSDB_DB_NAME_LEN] = {0};
 
+  blockDataCleanup(pInfo->pRes);
+
   const char* name = tNameGetTableName(&pInfo->name);
   if (pInfo->showRewrite) {
     getDBNameFromCondition(pInfo->pCondition, dbName);