fix: rows number exceeds block capacity issue

source/dnode/vnode/inc/vnode.h

@@ -153,6 +153,8 @@ typedef struct SMTbCursor SMTbCursor;
 SMTbCursor *metaOpenTbCursor(SMeta *pMeta);
 void        metaCloseTbCursor(SMTbCursor *pTbCur);
 int32_t     metaTbCursorNext(SMTbCursor *pTbCur);
+int32_t     metaTbCursorPrev(SMTbCursor *pTbCur);
+
 #endif
 
 // tsdb

source/dnode/vnode/src/meta/metaQuery.c

@@ -311,7 +311,7 @@ void metaCloseTbCursor(SMTbCursor *pTbCur) {
   }
 }
 
-int metaTbCursorNext(SMTbCursor *pTbCur) {
+int32_t metaTbCursorNext(SMTbCursor *pTbCur) {
   int    ret;
   void  *pBuf;
   STbCfg tbCfg;
@@ -335,6 +335,31 @@ int metaTbCursorNext(SMTbCursor *pTbCur) {
   return 0;
 }
 
+int32_t metaTbCursorPrev(SMTbCursor *pTbCur) {
+  int    ret;
+  void  *pBuf;
+  STbCfg tbCfg;
+
+  for (;;) {
+    ret = tdbTbcPrev(pTbCur->pDbc, &pTbCur->pKey, &pTbCur->kLen, &pTbCur->pVal, &pTbCur->vLen);
+    if (ret < 0) {
+      return -1;
+    }
+
+    tDecoderClear(&pTbCur->mr.coder);
+
+    metaGetTableEntryByVersion(&pTbCur->mr, ((SUidIdxVal *)pTbCur->pVal)[0].version, *(tb_uid_t *)pTbCur->pKey);
+    if (pTbCur->mr.me.type == TSDB_SUPER_TABLE) {
+      continue;
+    }
+
+    break;
+  }
+
+  return 0;
+}
+
+
 SSchemaWrapper *metaGetTableSchema(SMeta *pMeta, tb_uid_t uid, int32_t sver, int lock) {
   void           *pData = NULL;
   int             nData = 0;

source/libs/executor/src/sysscanoperator.c

@@ -491,6 +491,7 @@ static SSDataBlock* sysTableScanUserTags(SOperatorInfo* pOperator) {
     pInfo->pCur = metaOpenTbCursor(pInfo->readHandle.meta);
   }
 
+  bool blockFull = false;
   while ((ret = metaTbCursorNext(pInfo->pCur)) == 0) {
     if (pInfo->pCur->mr.me.type != TSDB_CHILD_TABLE) {
       continue;
@@ -512,17 +513,24 @@ static SSDataBlock* sysTableScanUserTags(SOperatorInfo* pOperator) {
       T_LONG_JMP(pTaskInfo->env, terrno);
     }
 
-    sysTableUserTagsFillOneTableTags(pInfo, &smrSuperTable, &pInfo->pCur->mr, dbname, tableName, &numOfRows, dataBlock);
-
+    if ((smrSuperTable.me.stbEntry.schemaTag.nCols + numOfRows) > pOperator->resultInfo.capacity) {
+      metaTbCursorPrev(pInfo->pCur);
+      blockFull = true;
+    } else {
+      sysTableUserTagsFillOneTableTags(pInfo, &smrSuperTable, &pInfo->pCur->mr, dbname, tableName, &numOfRows, dataBlock);
+    }
+    
     metaReaderClear(&smrSuperTable);
 
-    if (numOfRows >= pOperator->resultInfo.capacity) {
+    if (blockFull || numOfRows >= pOperator->resultInfo.capacity) {
       relocateAndFilterSysTagsScanResult(pInfo, numOfRows, dataBlock, pOperator->exprSupp.pFilterInfo);
       numOfRows = 0;
 
       if (pInfo->pRes->info.rows > 0) {
         break;
       }
+
+      blockFull = false;
     }
   }
 

tests/script/tsim/query/sys_tbname.sim

@@ -86,4 +86,23 @@ if $data00 != @ins_tags@ then
 	return -1
 endi
 
+sql create stable stb(ts timestamp, f int) tags(t1 int, t2 int, t3 int, t4 int, t5 int);
+
+$i = 0
+$tbNum = 1000
+$tbPrefix = stb_tb
+while $i < $tbNum
+  $tb = $tbPrefix . $i
+  sql create table $tb using stb tags( $i , $i , $i , $i , $i )
+
+  $i = $i + 1
+endw
+
+sql select tag_value from information_schema.ins_tags where stable_name='stb';
+if $rows != 5000 then
+   print $rows
+        return -1
+endi
+
+
 #system sh/exec.sh -n dnode1 -s stop -x SIGINT