feat:add comment function

include/common/tmsg.h

@@ -1922,7 +1922,7 @@ typedef struct {
   // TSDB_ALTER_TABLE_UPDATE_OPTIONS
   int8_t  updateTTL;
   int32_t newTTL;
-  int8_t  updateComment;
+  int32_t newCommentLen;
   char*   newComment;
 } SVAlterTbReq;
 

include/libs/nodes/cmdnodes.h

@@ -87,6 +87,7 @@ typedef struct SAlterDatabaseStmt {
 
 typedef struct STableOptions {
   ENodeType  type;
+  bool       commentNull;
   char       comment[TSDB_TB_COMMENT_LEN];
   double     filesFactor;
   SNodeList* pRollupFuncs;

source/common/src/systable.c

@@ -124,7 +124,7 @@ static const SSysDbTableSchema userStbsSchema[] = {
     {.name = "columns", .bytes = 4, .type = TSDB_DATA_TYPE_INT},
     {.name = "tags", .bytes = 4, .type = TSDB_DATA_TYPE_INT},
     {.name = "last_update", .bytes = 8, .type = TSDB_DATA_TYPE_TIMESTAMP},
-    {.name = "table_comment", .bytes = 1024 + VARSTR_HEADER_SIZE, .type = TSDB_DATA_TYPE_VARCHAR},
+    {.name = "table_comment", .bytes = TSDB_TB_COMMENT_LEN + VARSTR_HEADER_SIZE, .type = TSDB_DATA_TYPE_VARCHAR},
 };
 
 static const SSysDbTableSchema streamSchema[] = {
@@ -148,7 +148,7 @@ static const SSysDbTableSchema userTblsSchema[] = {
     {.name = "uid", .bytes = 8, .type = TSDB_DATA_TYPE_BIGINT},
     {.name = "vgroup_id", .bytes = 4, .type = TSDB_DATA_TYPE_INT},
     {.name = "ttl", .bytes = 4, .type = TSDB_DATA_TYPE_INT},
-    {.name = "table_comment", .bytes = 512 + VARSTR_HEADER_SIZE, .type = TSDB_DATA_TYPE_VARCHAR},
+    {.name = "table_comment", .bytes = TSDB_TB_COMMENT_LEN + VARSTR_HEADER_SIZE, .type = TSDB_DATA_TYPE_VARCHAR},
     {.name = "type", .bytes = 20 + VARSTR_HEADER_SIZE, .type = TSDB_DATA_TYPE_VARCHAR},
 };
 

source/common/src/tmsg.c

@@ -561,7 +561,7 @@ int32_t tDeserializeSMCreateStbReq(void *buf, int32_t bufLen, SMCreateStbReq *pR
   }
 
   if (pReq->commentLen > 0) {
-    pReq->comment = taosMemoryMalloc(pReq->commentLen);
+    pReq->comment = taosMemoryMalloc(pReq->commentLen + 1);
     if (pReq->comment == NULL) return -1;
     if (tDecodeCStrTo(&decoder, pReq->comment) < 0) return -1;
   }
@@ -4350,7 +4350,7 @@ int tDecodeSVCreateTbReq(SDecoder *pCoder, SVCreateTbReq *pReq) {
   if (tDecodeI8(pCoder, &pReq->type) < 0) return -1;
   if (tDecodeI32(pCoder, &pReq->commentLen) < 0) return -1;
   if (pReq->commentLen > 0) {
-    pReq->comment = taosMemoryMalloc(pReq->commentLen);
+    pReq->comment = taosMemoryMalloc(pReq->commentLen + 1);
     if (pReq->comment == NULL) return -1;
     if (tDecodeCStrTo(pCoder, pReq->comment) < 0) return -1;
   }
@@ -4707,8 +4707,8 @@ int32_t tEncodeSVAlterTbReq(SEncoder *pEncoder, const SVAlterTbReq *pReq) {
       if (pReq->updateTTL) {
         if (tEncodeI32v(pEncoder, pReq->newTTL) < 0) return -1;
       }
-      if (tEncodeI8(pEncoder, pReq->updateComment) < 0) return -1;
-      if (pReq->updateComment) {
+      if (tEncodeI32v(pEncoder, pReq->newCommentLen) < 0) return -1;
+      if (pReq->newCommentLen > 0) {
         if (tEncodeCStr(pEncoder, pReq->newComment) < 0) return -1;
       }
       break;
@@ -4755,8 +4755,8 @@ int32_t tDecodeSVAlterTbReq(SDecoder *pDecoder, SVAlterTbReq *pReq) {
       if (pReq->updateTTL) {
         if (tDecodeI32v(pDecoder, &pReq->newTTL) < 0) return -1;
       }
-      if (tDecodeI8(pDecoder, &pReq->updateComment) < 0) return -1;
-      if (pReq->updateComment) {
+      if (tDecodeI32v(pDecoder, &pReq->newCommentLen) < 0) return -1;
+      if (pReq->newCommentLen > 0) {
         if (tDecodeCStr(pDecoder, &pReq->newComment) < 0) return -1;
       }
       break;

source/dnode/mgmt/mgmt_vnode/src/vmHandle.c

@@ -334,6 +334,7 @@ SArray *vmGetMsgHandles() {
   if (dmSetMgmtHandle(pArray, TDMT_VND_CANCEL_TASK, vmPutMsgToFetchQueue, 0) == NULL) goto _OVER;
   if (dmSetMgmtHandle(pArray, TDMT_VND_DROP_TASK, vmPutMsgToFetchQueue, 0) == NULL) goto _OVER;
   if (dmSetMgmtHandle(pArray, TDMT_VND_CREATE_STB, vmPutMsgToWriteQueue, 0) == NULL) goto _OVER;
+  if (dmSetMgmtHandle(pArray, TDMT_VND_DROP_TTL_TABLE, vmPutMsgToWriteQueue, 0) == NULL) goto _OVER;
   if (dmSetMgmtHandle(pArray, TDMT_VND_ALTER_STB, vmPutMsgToWriteQueue, 0) == NULL) goto _OVER;
   if (dmSetMgmtHandle(pArray, TDMT_VND_DROP_STB, vmPutMsgToWriteQueue, 0) == NULL) goto _OVER;
   if (dmSetMgmtHandle(pArray, TDMT_VND_CREATE_TABLE, vmPutMsgToWriteQueue, 0) == NULL) goto _OVER;

source/dnode/mnode/impl/src/mndMain.c

@@ -87,18 +87,17 @@ static void mndPushTtlTime(SMnode *pMnode) {
     if (pIter == NULL) break;
 
     int32_t contLen = sizeof(SMsgHead) + sizeof(int32_t);
-
-    SMsgHead *pHead = taosMemoryMalloc(contLen);
+    SMsgHead   *pHead = rpcMallocCont(contLen);
     if (pHead == NULL) {
       mError("ttl time malloc err. contLen:%d", contLen);
       sdbRelease(pSdb, pVgroup);
       continue;
     }
-    pHead->contLen = htonl(pHead->contLen);
-    pHead->vgId = htonl(pHead->vgId);
+    pHead->contLen = htonl(contLen);
+    pHead->vgId = htonl(pVgroup->vgId);
 
     int32_t t = taosGetTimestampSec();
-    *(int32_t*)(pHead + sizeof(SMsgHead)) = htonl(t);
+    *(int32_t*)(POINTER_SHIFT(pHead, sizeof(SMsgHead))) = htonl(t);
 
     SRpcMsg rpcMsg = {.msgType = TDMT_VND_DROP_TTL_TABLE, .pCont = pHead, .contLen = contLen};
 
@@ -109,7 +108,6 @@ static void mndPushTtlTime(SMnode *pMnode) {
     }
     mError("ttl time seed succ. time:%d", t);
     sdbRelease(pSdb, pVgroup);
-    taosMemoryFree(pHead);
   }
 }
 
@@ -138,8 +136,6 @@ static void *mndThreadFp(void *param) {
     if (lastTime % (tsTelemInterval * 10) == 0) {
       mndPullupTelem(pMnode);
     }
-
-
   }
 
   return NULL;

source/dnode/mnode/impl/src/mndStb.c

@@ -117,7 +117,7 @@ SSdbRaw *mndStbActionEncode(SStbObj *pStb) {
   }
 
   if (pStb->commentLen > 0) {
-    SDB_SET_BINARY(pRaw, dataPos, pStb->comment, pStb->commentLen, _OVER)
+    SDB_SET_BINARY(pRaw, dataPos, pStb->comment, pStb->commentLen + 1, _OVER)
   }
   if (pStb->ast1Len > 0) {
     SDB_SET_BINARY(pRaw, dataPos, pStb->pAst1, pStb->ast1Len, _OVER)
@@ -204,9 +204,9 @@ static SSdbRow *mndStbActionDecode(SSdbRaw *pRaw) {
   }
 
   if (pStb->commentLen > 0) {
-    pStb->comment = taosMemoryCalloc(pStb->commentLen, 1);
+    pStb->comment = taosMemoryCalloc(pStb->commentLen + 1, 1);
     if (pStb->comment == NULL) goto _OVER;
-    SDB_GET_BINARY(pRaw, dataPos, pStb->comment, pStb->commentLen, _OVER)
+    SDB_GET_BINARY(pRaw, dataPos, pStb->comment, pStb->commentLen + 1, _OVER)
   }
   if (pStb->ast1Len > 0) {
     pStb->pAst1 = taosMemoryCalloc(pStb->ast1Len, 1);
@@ -281,7 +281,7 @@ static int32_t mndStbActionUpdate(SSdb *pSdb, SStbObj *pOld, SStbObj *pNew) {
   }
 
   if (pOld->commentLen < pNew->commentLen) {
-    void *comment = taosMemoryMalloc(pNew->commentLen);
+    void *comment = taosMemoryMalloc(pNew->commentLen + 1);
     if (comment != NULL) {
       taosMemoryFree(pOld->comment);
       pOld->comment = comment;
@@ -326,7 +326,7 @@ static int32_t mndStbActionUpdate(SSdb *pSdb, SStbObj *pOld, SStbObj *pNew) {
   memcpy(pOld->pColumns, pNew->pColumns, pOld->numOfColumns * sizeof(SSchema));
   memcpy(pOld->pTags, pNew->pTags, pOld->numOfTags * sizeof(SSchema));
   if (pNew->commentLen != 0) {
-    memcpy(pOld->comment, pNew->comment, pNew->commentLen);
+    memcpy(pOld->comment, pNew->comment, pNew->commentLen + 1);
   }
   if (pNew->ast1Len != 0) {
     memcpy(pOld->pAst1, pNew->pAst1, pNew->ast1Len);
@@ -671,12 +671,12 @@ int32_t mndBuildStbFromReq(SMnode *pMnode, SStbObj *pDst, SMCreateStbReq *pCreat
   pDst->numOfTags = pCreate->numOfTags;
   pDst->commentLen = pCreate->commentLen;
   if (pDst->commentLen > 0) {
-    pDst->comment = taosMemoryCalloc(pDst->commentLen, 1);
+    pDst->comment = taosMemoryCalloc(pDst->commentLen + 1, 1);
     if (pDst->comment == NULL) {
       terrno = TSDB_CODE_OUT_OF_MEMORY;
       return -1;
     }
-    memcpy(pDst->comment, pCreate->comment, pDst->commentLen);
+    memcpy(pDst->comment, pCreate->comment, pDst->commentLen + 1);
   }
 
   pDst->ast1Len = pCreate->ast1Len;
@@ -892,13 +892,16 @@ static int32_t mndUpdateStbCommentAndTTL(const SStbObj *pOld, SStbObj *pNew, cha
                                          int32_t ttl) {
   if (commentLen > 0) {
     pNew->commentLen = commentLen;
-    pNew->comment = taosMemoryCalloc(1, commentLen);
+    pNew->comment = taosMemoryCalloc(1, commentLen + 1);
     if (pNew->comment == NULL) {
       terrno = TSDB_CODE_OUT_OF_MEMORY;
       return -1;
     }
-    memcpy(pNew->comment, pComment, commentLen);
+    memcpy(pNew->comment, pComment, commentLen + 1);
+  } else if(commentLen == 0){
+    pNew->commentLen = 0;
   }
+
   if (ttl >= 0) {
     pNew->ttl = ttl;
   }
@@ -1848,17 +1851,17 @@ static int32_t mndRetrieveStb(SRpcMsg *pReq, SShowObj *pShow, SSDataBlock *pBloc
     pColInfo = taosArrayGet(pBlock->pDataBlock, cols++);
     colDataAppend(pColInfo, numOfRows, (const char *)&pStb->updateTime, false);  // number of tables
 
-    char *p = taosMemoryCalloc(1, pStb->commentLen + 1 + VARSTR_HEADER_SIZE);  // check malloc failures
-    if (p != NULL) {
-      if (pStb->commentLen != 0) {
-        STR_TO_VARSTR(p, pStb->comment);
-      } else {
-        STR_TO_VARSTR(p, "");
-      }
-
-      pColInfo = taosArrayGet(pBlock->pDataBlock, cols);
-      colDataAppend(pColInfo, numOfRows, (const char *)p, false);
-      taosMemoryFree(p);
+    pColInfo = taosArrayGet(pBlock->pDataBlock, cols);
+    if (pStb->commentLen > 0) {
+      char comment[TSDB_TB_COMMENT_LEN + VARSTR_HEADER_SIZE] = {0};
+      STR_TO_VARSTR(comment, pStb->comment);
+      colDataAppend(pColInfo, numOfRows, comment, false);
+    } else if(pStb->commentLen == 0) {
+      char comment[VARSTR_HEADER_SIZE + VARSTR_HEADER_SIZE] = {0};
+      STR_TO_VARSTR(comment, "");
+      colDataAppend(pColInfo, numOfRows, comment, false);
+    } else {
+      colDataAppendNULL(pColInfo, numOfRows);
     }
 
     numOfRows++;

source/dnode/vnode/inc/vnode.h

@@ -210,6 +210,7 @@ struct SMetaEntry {
     struct {
       int64_t  ctime;
       int32_t  ttlDays;
+      int32_t  commentLen;
       char    *comment;
       tb_uid_t suid;
       uint8_t *pTags;
@@ -217,6 +218,7 @@ struct SMetaEntry {
     struct {
       int64_t        ctime;
       int32_t        ttlDays;
+      int32_t        commentLen;
       char          *comment;
       int32_t        ncid;  // next column id
       SSchemaWrapper schemaRow;

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

@@ -29,14 +29,20 @@ int metaEncodeEntry(SEncoder *pCoder, const SMetaEntry *pME) {
   } else if (pME->type == TSDB_CHILD_TABLE) {
     if (tEncodeI64(pCoder, pME->ctbEntry.ctime) < 0) return -1;
     if (tEncodeI32(pCoder, pME->ctbEntry.ttlDays) < 0) return -1;
-    if (tEncodeCStr(pCoder, pME->ctbEntry.comment) < 0) return -1;
+    if (tEncodeI32(pCoder, pME->ctbEntry.commentLen) < 0) return -1;
+    if (pME->ctbEntry.commentLen > 0){
+      if (tEncodeCStr(pCoder, pME->ctbEntry.comment) < 0) return -1;
+    }
     if (tEncodeI64(pCoder, pME->ctbEntry.suid) < 0) return -1;
     debugCheckTags((STag*)pME->ctbEntry.pTags); // TODO: remove after debug
     if (tEncodeTag(pCoder, (const STag *)pME->ctbEntry.pTags) < 0) return -1;
   } else if (pME->type == TSDB_NORMAL_TABLE) {
     if (tEncodeI64(pCoder, pME->ntbEntry.ctime) < 0) return -1;
     if (tEncodeI32(pCoder, pME->ntbEntry.ttlDays) < 0) return -1;
-    if (tEncodeCStr(pCoder, pME->ntbEntry.comment) < 0) return -1;
+    if (tEncodeI32(pCoder, pME->ntbEntry.commentLen) < 0) return -1;
+    if (pME->ntbEntry.commentLen > 0){
+      if (tEncodeCStr(pCoder, pME->ntbEntry.comment) < 0) return -1;
+    }
     if (tEncodeI32v(pCoder, pME->ntbEntry.ncid) < 0) return -1;
     if (tEncodeSSchemaWrapper(pCoder, &pME->ntbEntry.schemaRow) < 0) return -1;
   } else if (pME->type == TSDB_TSMA_TABLE) {
@@ -63,14 +69,21 @@ int metaDecodeEntry(SDecoder *pCoder, SMetaEntry *pME) {
   } else if (pME->type == TSDB_CHILD_TABLE) {
     if (tDecodeI64(pCoder, &pME->ctbEntry.ctime) < 0) return -1;
     if (tDecodeI32(pCoder, &pME->ctbEntry.ttlDays) < 0) return -1;
-    if (tDecodeCStr(pCoder, &pME->ctbEntry.comment) < 0) return -1;
+    if (tDecodeI32(pCoder, &pME->ctbEntry.commentLen) < 0) return -1;
+    if (pME->ctbEntry.commentLen > 0){
+      if (tDecodeCStr(pCoder, &pME->ctbEntry.comment) < 0)
+        return -1;
+    }
     if (tDecodeI64(pCoder, &pME->ctbEntry.suid) < 0) return -1;
     if (tDecodeTag(pCoder, (STag **)&pME->ctbEntry.pTags) < 0) return -1;  // (TODO)
     debugCheckTags((STag*)pME->ctbEntry.pTags); // TODO: remove after debug
   } else if (pME->type == TSDB_NORMAL_TABLE) {
     if (tDecodeI64(pCoder, &pME->ntbEntry.ctime) < 0) return -1;
     if (tDecodeI32(pCoder, &pME->ntbEntry.ttlDays) < 0) return -1;
-    if (tDecodeCStr(pCoder, &pME->ntbEntry.comment) < 0) return -1;
+    if (tDecodeI32(pCoder, &pME->ntbEntry.commentLen) < 0) return -1;
+    if (pME->ntbEntry.commentLen > 0){
+      if (tDecodeCStr(pCoder, &pME->ntbEntry.comment) < 0) return -1;
+    }
     if (tDecodeI32v(pCoder, &pME->ntbEntry.ncid) < 0) return -1;
     if (tDecodeSSchemaWrapperEx(pCoder, &pME->ntbEntry.schemaRow) < 0) return -1;
   } else if (pME->type == TSDB_TSMA_TABLE) {

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

@@ -320,12 +320,14 @@ int metaCreateTable(SMeta *pMeta, int64_t version, SVCreateTbReq *pReq) {
   if (me.type == TSDB_CHILD_TABLE) {
     me.ctbEntry.ctime = pReq->ctime;
     me.ctbEntry.ttlDays = pReq->ttl;
+    me.ctbEntry.commentLen = pReq->commentLen;
     me.ctbEntry.comment = pReq->comment;
     me.ctbEntry.suid = pReq->ctb.suid;
     me.ctbEntry.pTags = pReq->ctb.pTag;
   } else {
     me.ntbEntry.ctime = pReq->ctime;
     me.ntbEntry.ttlDays = pReq->ttl;
+    me.ntbEntry.commentLen = pReq->commentLen;
     me.ntbEntry.comment = pReq->comment;
     me.ntbEntry.schemaRow = pReq->ntb.schemaRow;
     me.ntbEntry.ncid = me.ntbEntry.schemaRow.pSchema[me.ntbEntry.schemaRow.nCols - 1].colId + 1;
@@ -398,7 +400,8 @@ static void metaBuildTtlIdxKey(STtlIdxKey *ttlKey, const SMetaEntry *pME){
 
   if (ttlDays <= 0) return;
 
-  ttlKey->dtime = ctime + ttlDays * 24 * 60 * 60;
+//  ttlKey->dtime = ctime / 1000 + ttlDays * 24 * 60 * 60;
+  ttlKey->dtime = ctime / 1000 + ttlDays;
   ttlKey->uid = pME->uid;
 }
 
@@ -582,7 +585,6 @@ static int metaAlterTableColumn(SMeta *pMeta, int64_t version, SVAlterTbReq *pAl
   // save to table db
   metaSaveToTbDb(pMeta, &entry);
 
-  tdbTbcOpen(pMeta->pUidIdx, &pUidIdxc, &pMeta->txn);
   tdbTbcUpsert(pUidIdxc, &entry.uid, sizeof(tb_uid_t), &version, sizeof(version), 0);
 
   metaSaveToSkmDb(pMeta, &entry);
@@ -809,22 +811,25 @@ static int metaUpdateTableOptions(SMeta *pMeta, int64_t version, SVAlterTbReq *p
       entry.ctbEntry.ttlDays = pAlterTbReq->newTTL;
       metaUpdateTtlIdx(pMeta, &entry);
     }
-    if(pAlterTbReq->updateComment) entry.ctbEntry.comment = pAlterTbReq->newComment;
+    if(pAlterTbReq->newCommentLen >= 0) {
+      entry.ctbEntry.commentLen = pAlterTbReq->newCommentLen;
+      entry.ctbEntry.comment = pAlterTbReq->newComment;
+    }
   } else {
     if(pAlterTbReq->updateTTL) {
       metaDeleteTtlIdx(pMeta, &entry);
       entry.ntbEntry.ttlDays = pAlterTbReq->newTTL;
       metaUpdateTtlIdx(pMeta, &entry);
     }
-    if(pAlterTbReq->updateComment) entry.ntbEntry.comment = pAlterTbReq->newComment;
+    if(pAlterTbReq->newCommentLen >= 0) {
+      entry.ntbEntry.commentLen = pAlterTbReq->newCommentLen;
+      entry.ntbEntry.comment = pAlterTbReq->newComment;
+    }
   }
 
   // save to table db
   metaSaveToTbDb(pMeta, &entry);
-
-  tdbTbcOpen(pMeta->pUidIdx, &pUidIdxc, &pMeta->txn);
   tdbTbcUpsert(pUidIdxc, &entry.uid, sizeof(tb_uid_t), &version, sizeof(version), 0);
-
   metaULock(pMeta);
 
   tdbTbcClose(pTbDbc);

source/dnode/vnode/src/vnd/vnodeSvr.c

@@ -34,7 +34,7 @@ int32_t vnodePreprocessReq(SVnode *pVnode, SRpcMsg *pMsg) {
 
   switch (pMsg->msgType) {
     case TDMT_VND_CREATE_TABLE: {
-      int64_t ctime = taosGetTimestampSec();
+      int64_t ctime = taosGetTimestampMs();
       int32_t nReqs;
 
       tDecoderInit(&dc, (uint8_t *)pMsg->pCont + sizeof(SMsgHead), pMsg->contLen - sizeof(SMsgHead));
@@ -61,7 +61,7 @@ int32_t vnodePreprocessReq(SVnode *pVnode, SRpcMsg *pMsg) {
       SSubmitMsgIter msgIter = {0};
       SSubmitReq    *pSubmitReq = (SSubmitReq *)pMsg->pCont;
       SSubmitBlk    *pBlock = NULL;
-      int64_t        ctime = taosGetTimestampSec();
+      int64_t        ctime = taosGetTimestampMs();
       tb_uid_t       uid;
 
       tInitSubmitMsgIter(pSubmitReq, &msgIter);
@@ -106,7 +106,7 @@ int32_t vnodeProcessWriteReq(SVnode *pVnode, SRpcMsg *pMsg, int64_t version, SRp
   int32_t len;
   int32_t ret;
 
-  vTrace("vgId:%d, start to process write request %s, index:%" PRId64, TD_VID(pVnode), TMSG_INFO(pMsg->msgType),
+  vError("vgId:%d, start to process write request %s, index:%" PRId64, TD_VID(pVnode), TMSG_INFO(pMsg->msgType),
          version);
 
   pVnode->state.applied = version;
@@ -404,7 +404,9 @@ static int32_t vnodeProcessDropTtlTbReq(SVnode *pVnode, int64_t version, void *p
   if(ret != 0){
     goto end;
   }
-  tqUpdateTbUidList(pVnode->pTq, tbUids, false);
+  if(taosArrayGetSize(tbUids) > 0){
+    tqUpdateTbUidList(pVnode->pTq, tbUids, false);
+  }
 
 end:
   taosArrayDestroy(tbUids);

source/libs/executor/src/scanoperator.c

@@ -1299,12 +1299,6 @@ static SSDataBlock* doSysTableScan(SOperatorInfo* pOperator) {
         pColInfoData = taosArrayGet(p->pDataBlock, 6);
         colDataAppend(pColInfoData, numOfRows, (char*)&vgId, false);
 
-        // table comment
-        // todo: set the correct comment
-        pColInfoData = taosArrayGet(p->pDataBlock, 8);
-        colDataAppendNULL(pColInfoData, numOfRows);
-
-        char    str[256] = {0};
         int32_t tableType = pInfo->pCur->mr.me.type;
         if (tableType == TSDB_CHILD_TABLE) {
           // create time
@@ -1321,11 +1315,25 @@ static SSDataBlock* doSysTableScan(SOperatorInfo* pOperator) {
           colDataAppend(pColInfoData, numOfRows, (char*)&mr.me.stbEntry.schemaRow.nCols, false);
 
           // super table name
-          STR_TO_VARSTR(str, mr.me.name);
+          STR_TO_VARSTR(n, mr.me.name);
           pColInfoData = taosArrayGet(p->pDataBlock, 4);
-          colDataAppend(pColInfoData, numOfRows, str, false);
+          colDataAppend(pColInfoData, numOfRows, n, false);
           metaReaderClear(&mr);
 
+          // table comment
+          pColInfoData = taosArrayGet(p->pDataBlock, 8);
+          if(pInfo->pCur->mr.me.ctbEntry.commentLen > 0) {
+            char comment[TSDB_TB_COMMENT_LEN + VARSTR_HEADER_SIZE] = {0};
+            STR_TO_VARSTR(comment, pInfo->pCur->mr.me.ctbEntry.comment);
+            colDataAppend(pColInfoData, numOfRows, comment, false);
+          }else if(pInfo->pCur->mr.me.ctbEntry.commentLen == 0) {
+            char comment[VARSTR_HEADER_SIZE + VARSTR_HEADER_SIZE] = {0};
+            STR_TO_VARSTR(comment, "");
+            colDataAppend(pColInfoData, numOfRows, comment, false);
+          }else{
+            colDataAppendNULL(pColInfoData, numOfRows);
+          }
+
           // uid
           pColInfoData = taosArrayGet(p->pDataBlock, 5);
           colDataAppend(pColInfoData, numOfRows, (char*)&pInfo->pCur->mr.me.uid, false);
@@ -1334,7 +1342,7 @@ static SSDataBlock* doSysTableScan(SOperatorInfo* pOperator) {
           pColInfoData = taosArrayGet(p->pDataBlock, 7);
           colDataAppend(pColInfoData, numOfRows, (char*)&pInfo->pCur->mr.me.ctbEntry.ttlDays, false);
 
-          STR_TO_VARSTR(str, "CHILD_TABLE");
+          STR_TO_VARSTR(n, "CHILD_TABLE");
         } else if (tableType == TSDB_NORMAL_TABLE) {
           // create time
           pColInfoData = taosArrayGet(p->pDataBlock, 2);
@@ -1348,6 +1356,20 @@ static SSDataBlock* doSysTableScan(SOperatorInfo* pOperator) {
           pColInfoData = taosArrayGet(p->pDataBlock, 4);
           colDataAppendNULL(pColInfoData, numOfRows);
 
+          // table comment
+          pColInfoData = taosArrayGet(p->pDataBlock, 8);
+          if(pInfo->pCur->mr.me.ntbEntry.commentLen > 0) {
+            char comment[TSDB_TB_COMMENT_LEN + VARSTR_HEADER_SIZE] = {0};
+            STR_TO_VARSTR(comment, pInfo->pCur->mr.me.ntbEntry.comment);
+            colDataAppend(pColInfoData, numOfRows, comment, false);
+          }else if(pInfo->pCur->mr.me.ntbEntry.commentLen == 0) {
+            char comment[VARSTR_HEADER_SIZE + VARSTR_HEADER_SIZE] = {0};
+            STR_TO_VARSTR(comment, "");
+            colDataAppend(pColInfoData, numOfRows, comment, false);
+          }else{
+            colDataAppendNULL(pColInfoData, numOfRows);
+          }
+
           // uid
           pColInfoData = taosArrayGet(p->pDataBlock, 5);
           colDataAppend(pColInfoData, numOfRows, (char*)&pInfo->pCur->mr.me.uid, false);
@@ -1356,11 +1378,11 @@ static SSDataBlock* doSysTableScan(SOperatorInfo* pOperator) {
           pColInfoData = taosArrayGet(p->pDataBlock, 7);
           colDataAppend(pColInfoData, numOfRows, (char*)&pInfo->pCur->mr.me.ntbEntry.ttlDays, false);
 
-          STR_TO_VARSTR(str, "NORMAL_TABLE");
+          STR_TO_VARSTR(n, "NORMAL_TABLE");
         }
 
         pColInfoData = taosArrayGet(p->pDataBlock, 9);
-        colDataAppend(pColInfoData, numOfRows, str, false);
+        colDataAppend(pColInfoData, numOfRows, n, false);
 
         if (++numOfRows >= pOperator->resultInfo.capacity) {
           break;

source/libs/parser/src/parAstCreater.c

@@ -865,6 +865,7 @@ SNode* createDefaultTableOptions(SAstCreateContext* pCxt) {
   CHECK_OUT_OF_MEM(pOptions);
   pOptions->filesFactor = TSDB_DEFAULT_ROLLUP_FILE_FACTOR;
   pOptions->ttl = TSDB_DEFAULT_TABLE_TTL;
+  pOptions->commentNull = true;    // mark null
   return (SNode*)pOptions;
 }
 
@@ -874,6 +875,7 @@ SNode* createAlterTableOptions(SAstCreateContext* pCxt) {
   CHECK_OUT_OF_MEM(pOptions);
   pOptions->filesFactor = -1;
   pOptions->ttl = -1;
+  pOptions->commentNull = true;    // mark null
   return (SNode*)pOptions;
 }
 
@@ -882,6 +884,7 @@ SNode* setTableOption(SAstCreateContext* pCxt, SNode* pOptions, ETableOptionType
   switch (type) {
     case TABLE_OPTION_COMMENT:
       if (checkComment(pCxt, (SToken*)pVal, true)) {
+        ((STableOptions*)pOptions)->commentNull = false;
         copyStringFormStringToken((SToken*)pVal, ((STableOptions*)pOptions)->comment,
                                   sizeof(((STableOptions*)pOptions)->comment));
       }

source/libs/parser/src/parTranslater.c

@@ -3055,12 +3055,14 @@ static int32_t buildCreateStbReq(STranslateContext* pCxt, SCreateTableStmt* pStm
   columnDefNodeToField(pStmt->pTags, &pReq->pTags);
   pReq->numOfColumns = LIST_LENGTH(pStmt->pCols);
   pReq->numOfTags = LIST_LENGTH(pStmt->pTags);
-  if ('\0' != pStmt->pOptions->comment[0]) {
+  if(pStmt->pOptions->commentNull == false){
     pReq->comment = strdup(pStmt->pOptions->comment);
     if (NULL == pReq->comment) {
       return TSDB_CODE_OUT_OF_MEMORY;
     }
-    pReq->commentLen = strlen(pStmt->pOptions->comment) + 1;
+    pReq->commentLen = strlen(pStmt->pOptions->comment);
+  }else{
+    pReq->commentLen = -1;
   }
 
   SName tableName;
@@ -3109,13 +3111,16 @@ static int32_t translateDropSuperTable(STranslateContext* pCxt, SDropSuperTableS
 static int32_t setAlterTableField(SAlterTableStmt* pStmt, SMAlterStbReq* pAlterReq) {
   if (TSDB_ALTER_TABLE_UPDATE_OPTIONS == pStmt->alterType) {
     pAlterReq->ttl = pStmt->pOptions->ttl;
-    if ('\0' != pStmt->pOptions->comment[0]) {
+    if (pStmt->pOptions->commentNull == false) {
       pAlterReq->comment = strdup(pStmt->pOptions->comment);
       if (NULL == pAlterReq->comment) {
         return TSDB_CODE_OUT_OF_MEMORY;
       }
-      pAlterReq->commentLen = strlen(pStmt->pOptions->comment) + 1;
+      pAlterReq->commentLen = strlen(pStmt->pOptions->comment);
+    }else{
+      pAlterReq->commentLen = -1;
     }
+
     return TSDB_CODE_SUCCESS;
   }
 
@@ -4253,12 +4258,14 @@ static int32_t buildNormalTableBatchReq(int32_t acctId, const SCreateTableStmt*
   req.type = TD_NORMAL_TABLE;
   req.name = strdup(pStmt->tableName);
   req.ttl = pStmt->pOptions->ttl;
-  if ('\0' != pStmt->pOptions->comment[0]) {
+  if (pStmt->pOptions->commentNull == false) {
     req.comment = strdup(pStmt->pOptions->comment);
     if (NULL == req.comment) {
       return TSDB_CODE_OUT_OF_MEMORY;
     }
-    req.commentLen = strlen(pStmt->pOptions->comment) + 1;
+    req.commentLen = strlen(pStmt->pOptions->comment);
+  }else{
+    req.commentLen = -1;
   }
   req.ntb.schemaRow.nCols = LIST_LENGTH(pStmt->pCols);
   req.ntb.schemaRow.version = 1;
@@ -4411,9 +4418,11 @@ static void addCreateTbReqIntoVgroup(int32_t acctId, SHashObj* pVgroupHashmap, S
   req.type = TD_CHILD_TABLE;
   req.name = strdup(pStmt->tableName);
   req.ttl  = pStmt->pOptions->ttl;
-  if ('\0' != pStmt->pOptions->comment[0]) {
+  if (pStmt->pOptions->commentNull == false) {
     req.comment = strdup(pStmt->pOptions->comment);
-    req.commentLen = strlen(pStmt->pOptions->comment) + 1;
+    req.commentLen = strlen(pStmt->pOptions->comment);
+  } else{
+    req.commentLen = -1;
   }
   req.ctb.suid = suid;
   req.ctb.pTag = (uint8_t*)pTag;
@@ -4993,11 +5002,16 @@ static int32_t buildUpdateOptionsReq(STranslateContext* pCxt, SAlterTableStmt* p
     }
   }
 
-  if (TSDB_CODE_SUCCESS == code && '\0' != pStmt->pOptions->comment[0]) {
-    pReq->updateComment = true;
-    pReq->newComment = strdup(pStmt->pOptions->comment);
-    if (NULL == pReq->newComment) {
-      code = TSDB_CODE_OUT_OF_MEMORY;
+  if (TSDB_CODE_SUCCESS == code){
+    if(pStmt->pOptions->commentNull == false) {
+      pReq->newComment = strdup(pStmt->pOptions->comment);
+      if (NULL == pReq->newComment) {
+        code = TSDB_CODE_OUT_OF_MEMORY;
+      }
+      pReq->newCommentLen = strlen(pReq->newComment);
+    }
+    else{
+      pReq->newCommentLen = -1;
     }
   }
 

source/libs/parser/test/parInitialATest.cpp

@@ -91,7 +91,7 @@ TEST_F(ParserInitialATest, alterSTable) {
     expect.ttl = ttl;
     if (nullptr != pComment) {
       expect.comment = strdup(pComment);
-      expect.commentLen = strlen(pComment) + 1;
+      expect.commentLen = strlen(pComment);
     }
 
     expect.numOfFields = numOfFields;
@@ -252,7 +252,7 @@ TEST_F(ParserInitialATest, alterTable) {
       expect.newTTL = ttl;
     }
     if (nullptr != pComment) {
-      expect.updateComment = true;
+      expect.newCommentLen = strlen(pComment);
       expect.newComment = pComment;
     }
   };
@@ -291,9 +291,10 @@ TEST_F(ParserInitialATest, alterTable) {
     ASSERT_EQ(memcmp(req.pTagVal, expect.pTagVal, expect.nTagVal), 0);
     ASSERT_EQ(req.updateTTL, expect.updateTTL);
     ASSERT_EQ(req.newTTL, expect.newTTL);
-    ASSERT_EQ(req.updateComment, expect.updateComment);
     if (nullptr != expect.newComment) {
       ASSERT_EQ(std::string(req.newComment), std::string(expect.newComment));
+      ASSERT_EQ(req.newCommentLen, strlen(req.newComment));
+      ASSERT_EQ(expect.newCommentLen, strlen(expect.newComment));
     }
 
     tDecoderClear(&coder);

source/libs/parser/test/parInitialCTest.cpp

@@ -332,7 +332,7 @@ TEST_F(ParserInitialCTest, createStable) {
     expect.ttl = ttl;
     if (nullptr != pComment) {
       expect.comment = strdup(pComment);
-      expect.commentLen = strlen(pComment) + 1;
+      expect.commentLen = strlen(pComment);
     }
   };