fix(query): free the cursor when all data retrieved immediately.

source/libs/executor/inc/executorimpl.h

@@ -401,13 +401,12 @@ typedef struct SStreamBlockScanInfo {
 } SStreamBlockScanInfo;
 
 typedef struct SSysTableScanInfo {
-  SReadHandle readHandle;
-
   SRetrieveMetaTableRsp* pRsp;
   SRetrieveTableReq      req;
   SEpSet                 epSet;
   tsem_t                 ready;
 
+  SReadHandle         readHandle;
   int32_t             accountId;
   bool                showRewrite;
   SNode*              pCondition;  // db_name filter condition, to discard data that are not in current database

source/libs/executor/src/scanoperator.c

@@ -304,23 +304,28 @@ void addTagPseudoColumnData(STableScanInfo* pTableScanInfo, SSDataBlock* pBlock)
       setTbNameColData(pTableScanInfo->readHandle.meta, pBlock, pColInfoData, functionId);
     } else {  // these are tags
       const char* p = NULL;
-      if(pColInfoData->info.type == TSDB_DATA_TYPE_JSON){
-        const uint8_t *tmp = mr.me.ctbEntry.pTags;
-        char *data = taosMemoryCalloc(kvRowLen(tmp) + 1, 1);
-        if(data == NULL){
+      if (pColInfoData->info.type == TSDB_DATA_TYPE_JSON) {
+        const uint8_t* tmp = mr.me.ctbEntry.pTags;
+
+        char* data = taosMemoryCalloc(kvRowLen(tmp) + 1, 1);
+        if (data == NULL) {
+          metaReaderClear(&mr);
           qError("doTagScan calloc error:%d", kvRowLen(tmp) + 1);
           return;
         }
+
         *data = TSDB_DATA_TYPE_JSON;
-        memcpy(data+1, tmp, kvRowLen(tmp));
+        memcpy(data + 1, tmp, kvRowLen(tmp));
         p = data;
-      }else{
+      } else {
         p = metaGetTableTagVal(&mr.me, pExpr->base.pParam[0].pCol->colId);
       }
+
       for (int32_t i = 0; i < pBlock->info.rows; ++i) {
         colDataAppend(pColInfoData, i, p, (p == NULL));
       }
-      if(pColInfoData->info.type == TSDB_DATA_TYPE_JSON){
+
+      if (pColInfoData->info.type == TSDB_DATA_TYPE_JSON) {
         taosMemoryFree((void*)p);
       }
     }
@@ -339,8 +344,7 @@ void setTbNameColData(void* pMeta, const SSDataBlock* pBlock, SColumnInfoData* p
   colInfoDataEnsureCapacity(&infoData, 0, 1);
 
   colDataAppendInt64(&infoData, 0, (int64_t*) &pBlock->info.uid);
-  SScalarParam srcParam = {
-      .numOfRows = pBlock->info.rows, .param = pMeta, .columnData = &infoData};
+  SScalarParam srcParam = {.numOfRows = pBlock->info.rows, .param = pMeta, .columnData = &infoData};
 
   SScalarParam param = {.columnData = pColInfoData};
   fpSet.process(&srcParam, 1, &param);
@@ -1219,18 +1223,18 @@ static SSDataBlock* doSysTableScan(SOperatorInfo* pOperator) {
   // retrieve local table list info from vnode
   const char* name = tNameGetTableName(&pInfo->name);
   if (strncasecmp(name, TSDB_INS_TABLE_USER_TABLES, TSDB_TABLE_FNAME_LEN) == 0) {
+    if (pOperator->status == OP_EXEC_DONE) {
+      return NULL;
+    }
+
     // the retrieve is executed on the mnode, so return tables that belongs to the information schema database.
     if (pInfo->readHandle.mnd != NULL) {
-      if (pOperator->status == OP_EXEC_DONE) {
-        return NULL;
-      }
-
       buildSysDbTableInfo(pInfo, pOperator->resultInfo.capacity);
 
       doFilterResult(pInfo);
       pInfo->loadInfo.totalRows += pInfo->pRes->info.rows;
 
-      pOperator->status = OP_EXEC_DONE;
+      doSetOperatorCompleted(pOperator);
       return (pInfo->pRes->info.rows == 0) ? NULL : pInfo->pRes;
     } else {
       if (pInfo->pCur == NULL) {
@@ -1256,7 +1260,9 @@ static SSDataBlock* doSysTableScan(SOperatorInfo* pOperator) {
       blockDataEnsureCapacity(p, pOperator->resultInfo.capacity);
 
       char n[TSDB_TABLE_NAME_LEN + VARSTR_HEADER_SIZE] = {0};
-      while (metaTbCursorNext(pInfo->pCur) == 0) {
+
+      int32_t ret = 0;
+      while ((ret = metaTbCursorNext(pInfo->pCur)) == 0) {
         STR_TO_VARSTR(n, pInfo->pCur->mr.me.name);
 
         // table name
@@ -1339,6 +1345,13 @@ static SSDataBlock* doSysTableScan(SOperatorInfo* pOperator) {
         }
       }
 
+      // todo temporarily free the cursor here, the true reason why the free is not valid needs to be found
+      if (ret != 0) {
+        metaCloseTbCursor(pInfo->pCur);
+        pInfo->pCur = NULL;
+        doSetOperatorCompleted(pOperator);
+      }
+
       p->info.rows = numOfRows;
       pInfo->pRes->info.rows = numOfRows;