feature(query): support show table block distribution.

source/dnode/vnode/inc/vnode.h

@@ -116,7 +116,7 @@ typedef void *tsdbReaderT;
 #define BLOCK_LOAD_TABLE_SEQ_ORDER  2
 #define BLOCK_LOAD_TABLE_RR_ORDER   3
 
-tsdbReaderT *tsdbReaderOpen(SVnode *pVnode, SQueryTableDataCond *pCond, STableListInfo *tableInfoGroup, uint64_t qId,
+tsdbReaderT  tsdbReaderOpen(SVnode *pVnode, SQueryTableDataCond *pCond, STableListInfo *tableInfoGroup, uint64_t qId,
                             uint64_t taskId);
 tsdbReaderT  tsdbQueryCacheLast(SVnode *pVnode, SQueryTableDataCond *pCond, STableListInfo *groupList, uint64_t qId,
                                 void *pMemRef);

source/dnode/vnode/src/inc/vnodeInt.h

@@ -119,7 +119,7 @@ int          tsdbInsertData(STsdb* pTsdb, int64_t version, SSubmitReq* pMsg, SSu
 int32_t      tsdbInsertTableData(STsdb* pTsdb, int64_t version, SSubmitMsgIter* pMsgIter, SSubmitBlk* pBlock,
                                  SSubmitBlkRsp* pRsp);
 int32_t      tsdbDeleteTableData(STsdb* pTsdb, int64_t version, tb_uid_t suid, tb_uid_t uid, TSKEY sKey, TSKEY eKey);
-tsdbReaderT* tsdbReaderOpen(SVnode* pVnode, SQueryTableDataCond* pCond, STableListInfo* tableList, uint64_t qId,
+tsdbReaderT  tsdbReaderOpen(SVnode* pVnode, SQueryTableDataCond* pCond, STableListInfo* tableList, uint64_t qId,
                             uint64_t taskId);
 tsdbReaderT  tsdbQueryCacheLastT(STsdb* tsdb, SQueryTableDataCond* pCond, STableListInfo* tableList, uint64_t qId,
                                  void* pMemRef);

source/dnode/vnode/src/tsdb/tsdbRead.c

@@ -500,7 +500,7 @@ static int32_t setCurrentSchema(SVnode* pVnode, STsdbReadHandle* pTsdbReadHandle
   return TSDB_CODE_SUCCESS;
 }
 
-tsdbReaderT* tsdbReaderOpen(SVnode* pVnode, SQueryTableDataCond* pCond, STableListInfo* tableList, uint64_t qId,
+tsdbReaderT tsdbReaderOpen(SVnode* pVnode, SQueryTableDataCond* pCond, STableListInfo* tableList, uint64_t qId,
                             uint64_t taskId) {
   STsdbReadHandle* pTsdbReadHandle = tsdbQueryTablesImpl(pVnode, pCond, qId, taskId);
   if (pTsdbReadHandle == NULL) {
@@ -508,7 +508,7 @@ tsdbReaderT* tsdbReaderOpen(SVnode* pVnode, SQueryTableDataCond* pCond, STableLi
   }
 
   if (emptyQueryTimewindow(pTsdbReadHandle)) {
-    return (tsdbReaderT*)pTsdbReadHandle;
+    return (tsdbReaderT)pTsdbReadHandle;
   }
 
   // todo apply the lastkey of table check to avoid to load header file

source/libs/executor/inc/executorimpl.h

@@ -369,6 +369,8 @@ typedef struct SSysTableScanInfo {
 typedef struct SBlockDistInfo {
   SSDataBlock* pResBlock;
   void*        pHandle;
+  SReadHandle  readHandle;
+  uint64_t     uid;        // table uid
 } SBlockDistInfo;
 
 // todo remove this
@@ -735,7 +737,7 @@ SOperatorInfo* createSessionAggOperatorInfo(SOperatorInfo* downstream, SExprInfo
 SOperatorInfo* createGroupOperatorInfo(SOperatorInfo* downstream, SExprInfo* pExprInfo, int32_t numOfCols,
                                        SSDataBlock* pResultBlock, SArray* pGroupColList, SNode* pCondition,
                                        SExprInfo* pScalarExprInfo, int32_t numOfScalarExpr, SExecTaskInfo* pTaskInfo);
-SOperatorInfo* createDataBlockInfoScanOperator(void* dataReader, SExecTaskInfo* pTaskInfo);
+SOperatorInfo* createDataBlockInfoScanOperator(void* dataReader, SReadHandle* readHandle, uint64_t uid, SExecTaskInfo* pTaskInfo);
 
 SOperatorInfo* createStreamScanOperatorInfo(void* pDataReader, SReadHandle* pHandle,
     STableScanPhysiNode* pTableScanNode, SExecTaskInfo* pTaskInfo, STimeWindowAggSupp* pTwSup);

source/libs/executor/src/executorimpl.c

@@ -502,6 +502,9 @@ static int32_t doSetInputDataBlock(SOperatorInfo* pOperator, SqlFunctionCtx* pCt
       SFunctParam* pFuncParam = &pOneExpr->base.pParam[j];
       if (pFuncParam->type == FUNC_PARAM_TYPE_COLUMN) {
         int32_t slotId = pFuncParam->pCol->slotId;
+        if (slotId >= taosArrayGetSize(pBlock->pDataBlock)) {
+          slotId = taosArrayGetSize(pBlock->pDataBlock) - 1;
+        }
         pInput->pData[j] = taosArrayGet(pBlock->pDataBlock, slotId);
         pInput->totalRows = pBlock->info.rows;
         pInput->numOfRows = pBlock->info.rows;
@@ -2812,7 +2815,8 @@ int32_t getTableScanInfo(SOperatorInfo* pOperator, int32_t* order, int32_t* scan
   // todo add more information about exchange operation
   int32_t type = pOperator->operatorType;
   if (type == QUERY_NODE_PHYSICAL_PLAN_EXCHANGE || type == QUERY_NODE_PHYSICAL_PLAN_SYSTABLE_SCAN ||
-      type == QUERY_NODE_PHYSICAL_PLAN_STREAM_SCAN || type == QUERY_NODE_PHYSICAL_PLAN_TAG_SCAN) {
+      type == QUERY_NODE_PHYSICAL_PLAN_STREAM_SCAN || type == QUERY_NODE_PHYSICAL_PLAN_TAG_SCAN ||
+      type == QUERY_NODE_PHYSICAL_PLAN_BLOCK_DIST_SCAN) {
     *order = TSDB_ORDER_ASC;
     *scanFlag = MAIN_SCAN;
     return TSDB_CODE_SUCCESS;
@@ -2840,7 +2844,6 @@ static int32_t doOpenAggregateOptr(SOperatorInfo* pOperator) {
   SAggOperatorInfo* pAggInfo = pOperator->info;
 
   SExprSupp* pSup = &pOperator->exprSupp;
-  SOptrBasicInfo* pInfo = &pAggInfo->binfo;
   SOperatorInfo*  downstream = pOperator->pDownstream[0];
 
   int64_t st = taosGetTimestampUs();
@@ -4087,6 +4090,46 @@ SOperatorInfo* createOperatorTree(SPhysiNode* pPhyNode, SExecTaskInfo* pTaskInfo
       }
 
       return createTagScanOperatorInfo(pHandle, pScanPhyNode, pTableListInfo, pTaskInfo);
+    } else if (QUERY_NODE_PHYSICAL_PLAN_BLOCK_DIST_SCAN == type) {
+      SBlockDistScanPhysiNode* pBlockNode = (SBlockDistScanPhysiNode*) pPhyNode;
+      pTableListInfo->pTableList = taosArrayInit(4, sizeof(STableKeyInfo));
+
+      if (pBlockNode->tableType == TSDB_SUPER_TABLE) {
+        int32_t code = tsdbGetAllTableList(pHandle->meta, pBlockNode->uid, pTableListInfo->pTableList);
+        if (code != TSDB_CODE_SUCCESS) {
+          pTaskInfo->code = terrno;
+          return NULL;
+        }
+      } else {  // Create one table group.
+        STableKeyInfo info = {.lastKey = 0, .uid = pBlockNode->uid};
+        taosArrayPush(pTableListInfo->pTableList, &info);
+      }
+
+      SQueryTableDataCond cond = {0};
+
+      {
+        cond.order = TSDB_ORDER_ASC;
+        cond.numOfCols = 1;
+        cond.colList = taosMemoryCalloc(1, sizeof(SColumnInfo));
+        if (cond.colList == NULL) {
+          terrno = TSDB_CODE_QRY_OUT_OF_MEMORY;
+          return NULL;
+        }
+
+        cond.colList->colId = 1;
+        cond.colList->type = TSDB_DATA_TYPE_TIMESTAMP;
+        cond.colList->bytes = sizeof(TSKEY);
+
+        cond.numOfTWindows = 1;
+        cond.twindows = taosMemoryCalloc(1, sizeof(STimeWindow));
+        cond.twindows[0] = (STimeWindow){.skey = INT64_MIN, .ekey = INT64_MAX};
+        cond.suid = pBlockNode->suid;
+        cond.type = BLOCK_LOAD_OFFSET_SEQ_ORDER;
+      }
+      tsdbReaderT* pReader = tsdbReaderOpen(pHandle->vnode, &cond, pTableListInfo, queryId, taskId);
+      cleanupQueryTableDataCond(&cond);
+
+      return createDataBlockInfoScanOperator(pReader, pHandle, cond.suid, pTaskInfo);
     } else {
       ASSERT(0);
     }
@@ -4284,8 +4327,7 @@ SArray* extractColumnInfo(SNodeList* pNodeList) {
 
 tsdbReaderT doCreateDataReader(STableScanPhysiNode* pTableScanNode, SReadHandle* pHandle,
                                STableListInfo* pTableListInfo, uint64_t queryId, uint64_t taskId, SNode* pTagCond) {
-  int32_t code =
-      getTableList(pHandle->meta, &pTableScanNode->scan, pTableListInfo, pTagCond);
+  int32_t code = getTableList(pHandle->meta, &pTableScanNode->scan, pTableListInfo, pTagCond);
   if (code != TSDB_CODE_SUCCESS) {
     goto _error;
   }

source/libs/executor/src/scanoperator.c

@@ -13,6 +13,7 @@
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <vnode.h>
 #include "filter.h"
 #include "function.h"
 #include "functionMgt.h"
@@ -590,12 +591,12 @@ SOperatorInfo* createTableSeqScanOperatorInfo(void* pReadHandle, SExecTaskInfo*
   pInfo->dataReader = pReadHandle;
   //  pInfo->prevGroupId       = -1;
 
-  pOperator->name = "TableSeqScanOperator";
+  pOperator->name         = "TableSeqScanOperator";
   pOperator->operatorType = QUERY_NODE_PHYSICAL_PLAN_TABLE_SEQ_SCAN;
-  pOperator->blocking = false;
-  pOperator->status = OP_NOT_OPENED;
-  pOperator->info = pInfo;
-  pOperator->pTaskInfo = pTaskInfo;
+  pOperator->blocking     = false;
+  pOperator->status       = OP_NOT_OPENED;
+  pOperator->info         = pInfo;
+  pOperator->pTaskInfo    = pTaskInfo;
 
   pOperator->fpSet = createOperatorFpSet(operatorDummyOpenFn, doTableScanImpl, NULL, NULL, NULL, NULL, NULL, NULL);
   return pOperator;
@@ -606,16 +607,48 @@ static SSDataBlock* doBlockInfoScan(SOperatorInfo* pOperator) {
     return NULL;
   }
 
-  STableScanInfo* pTableScanInfo = pOperator->info;
+  SBlockDistInfo* pBlockScanInfo = pOperator->info;
 
   STableBlockDistInfo blockDistInfo = {0};
   blockDistInfo.maxRows = INT_MIN;
   blockDistInfo.minRows = INT_MAX;
 
-  tsdbGetFileBlocksDistInfo(pTableScanInfo->dataReader, &blockDistInfo);
-  blockDistInfo.numOfInmemRows = (int32_t)tsdbGetNumOfRowsInMemTable(pTableScanInfo->dataReader);
+  SMetaReader mr = {0};
+  metaReaderInit(&mr, pBlockScanInfo->readHandle.meta, 0);
+  metaGetTableEntryByUid(&mr, pBlockScanInfo->uid);
+  if (mr.me.type == TSDB_SUPER_TABLE) {
+    int32_t numOfCols = mr.me.stbEntry.schemaRow.nCols;
+    int32_t rowLen = 0;
+    for(int32_t i = 0; i < numOfCols; ++i) {
+      rowLen += mr.me.stbEntry.schemaRow.pSchema[i].bytes;
+    }
+    blockDistInfo.rowSize = rowLen;
+  } else if (mr.me.type == TSDB_CHILD_TABLE) {
+    uint64_t suid = mr.me.ctbEntry.suid;
+    metaGetTableEntryByUid(&mr, suid);
+    int32_t numOfCols = mr.me.stbEntry.schemaRow.nCols;
+
+    int32_t rowLen = 0;
+    for(int32_t i = 0; i < numOfCols; ++i) {
+      rowLen += mr.me.stbEntry.schemaRow.pSchema[i].bytes;
+    }
+    blockDistInfo.rowSize = rowLen;
+
+  } else if (mr.me.type == TSDB_NORMAL_TABLE) {
+    int32_t numOfCols = mr.me.ntbEntry.schemaRow.nCols;
+    int32_t rowLen = 0;
+    for(int32_t i = 0; i < numOfCols; ++i) {
+      rowLen += mr.me.ntbEntry.schemaRow.pSchema[i].bytes;
+    }
+    blockDistInfo.rowSize = rowLen;
+  }
+
+  metaReaderClear(&mr);
 
-  SSDataBlock* pBlock = pTableScanInfo->pResBlock;
+  tsdbGetFileBlocksDistInfo(pBlockScanInfo->pHandle, &blockDistInfo);
+  blockDistInfo.numOfInmemRows = (int32_t)tsdbGetNumOfRowsInMemTable(pBlockScanInfo->pHandle);
+
+  SSDataBlock* pBlock = pBlockScanInfo->pResBlock;
   pBlock->info.rows = 1;
 
   SColumnInfoData* pColInfo = taosArrayGet(pBlock->pDataBlock, 0);
@@ -625,6 +658,7 @@ static SSDataBlock* doBlockInfoScan(SOperatorInfo* pOperator) {
   tSerializeBlockDistInfo(varDataVal(p), len, &blockDistInfo);
   varDataSetLen(p, len);
 
+  colInfoDataEnsureCapacity(pColInfo, 0, 1);
   colDataAppend(pColInfo, 0, p, false);
   taosMemoryFree(p);
 
@@ -637,7 +671,7 @@ static void destroyBlockDistScanOperatorInfo(void* param, int32_t numOfOutput) {
   blockDataDestroy(pDistInfo->pResBlock);
 }
 
-SOperatorInfo* createDataBlockInfoScanOperator(void* dataReader, SExecTaskInfo* pTaskInfo) {
+SOperatorInfo* createDataBlockInfoScanOperator(void* dataReader, SReadHandle* readHandle, uint64_t uid, SExecTaskInfo* pTaskInfo) {
   SBlockDistInfo* pInfo = taosMemoryCalloc(1, sizeof(SBlockDistInfo));
   SOperatorInfo*  pOperator = taosMemoryCalloc(1, sizeof(SOperatorInfo));
   if (pInfo == NULL || pOperator == NULL) {
@@ -645,7 +679,9 @@ SOperatorInfo* createDataBlockInfoScanOperator(void* dataReader, SExecTaskInfo*
     goto _error;
   }
 
-  pInfo->pHandle = dataReader;
+  pInfo->pHandle    = dataReader;
+  pInfo->readHandle = *readHandle;
+  pInfo->uid        = uid;
 
   pInfo->pResBlock = taosMemoryCalloc(1, sizeof(SSDataBlock));
 
@@ -653,13 +689,14 @@ SOperatorInfo* createDataBlockInfoScanOperator(void* dataReader, SExecTaskInfo*
   infoData.info.type = TSDB_DATA_TYPE_VARCHAR;
   infoData.info.bytes = 1024;
 
+  pInfo->pResBlock->pDataBlock = taosArrayInit(1, sizeof(SColumnInfoData));
   taosArrayPush(pInfo->pResBlock->pDataBlock, &infoData);
 
-  pOperator->name = "DataBlockInfoScanOperator";
-  //  pOperator->operatorType = OP_TableBlockInfoScan;
-  pOperator->blocking = false;
-  pOperator->status = OP_NOT_OPENED;
-  pOperator->info = pInfo;
+  pOperator->name      = "DataBlockDistScanOperator";
+  pOperator->operatorType = QUERY_NODE_PHYSICAL_PLAN_BLOCK_DIST_SCAN;
+  pOperator->blocking  = false;
+  pOperator->status    = OP_NOT_OPENED;
+  pOperator->info      = pInfo;
   pOperator->pTaskInfo = pTaskInfo;
 
   pOperator->fpSet = createOperatorFpSet(operatorDummyOpenFn, doBlockInfoScan, NULL, NULL,

source/libs/function/inc/builtinsimpl.h

@@ -192,6 +192,8 @@ int32_t twaFunction(SqlFunctionCtx *pCtx);
 int32_t twaFinalize(struct SqlFunctionCtx *pCtx, SSDataBlock* pBlock);
 
 bool getSelectivityFuncEnv(SFunctionNode* pFunc, SFuncExecEnv* pEnv);
+
+bool blockDistSetup(SqlFunctionCtx *pCtx, SResultRowEntryInfo* pResultInfo);
 int32_t blockDistFunction(SqlFunctionCtx *pCtx);
 int32_t blockDistFinalize(SqlFunctionCtx* pCtx, SSDataBlock* pBlock);
 

source/libs/function/src/builtins.c

@@ -2523,6 +2523,7 @@ const SBuiltinFuncDefinition funcMgtBuiltins[] = {
     .classification = FUNC_MGT_AGG_FUNC,
     .translateFunc = translateBlockDistFunc,
     .getEnvFunc   = getBlockDistFuncEnv,
+    .initFunc     = blockDistSetup,
     .processFunc  = blockDistFunction,
     .finalizeFunc = blockDistFinalize
   },

source/libs/function/src/builtinsimpl.c

@@ -5008,7 +5008,19 @@ int32_t twaFinalize(struct SqlFunctionCtx* pCtx, SSDataBlock* pBlock) {
   return functionFinalize(pCtx, pBlock);
 }
 
+bool blockDistSetup(SqlFunctionCtx *pCtx, SResultRowEntryInfo* pResultInfo) {
+  if (!functionSetup(pCtx, pResultInfo)) {
+    return false;
+  }
+
+  STableBlockDistInfo* pInfo = GET_ROWCELL_INTERBUF(GET_RES_INFO(pCtx));
+  pInfo->minRows = INT32_MAX;
+  return true;
+}
+
 int32_t blockDistFunction(SqlFunctionCtx* pCtx) {
+  const int32_t BLOCK_DIST_RESULT_ROWS = 24;
+
   SInputColumnInfoData* pInput = &pCtx->input;
   SColumnInfoData*      pInputCol = pInput->pData[0];
 
@@ -5026,6 +5038,11 @@ int32_t blockDistFunction(SqlFunctionCtx* pCtx) {
   pDistInfo->totalRows += p1.totalRows;
   pDistInfo->numOfFiles += p1.numOfFiles;
 
+  pDistInfo->defMinRows = p1.defMinRows;
+  pDistInfo->defMaxRows = p1.defMaxRows;
+  pDistInfo->rowSize    = p1.rowSize;
+  pDistInfo->numOfSmallBlocks = p1.numOfSmallBlocks;
+
   if (pDistInfo->minRows > p1.minRows) {
     pDistInfo->minRows = p1.minRows;
   }
@@ -5037,7 +5054,7 @@ int32_t blockDistFunction(SqlFunctionCtx* pCtx) {
     pDistInfo->blockRowsHisto[i] += p1.blockRowsHisto[i];
   }
 
-  pResInfo->numOfRes = 1;
+  pResInfo->numOfRes = BLOCK_DIST_RESULT_ROWS;  // default output rows
   return TSDB_CODE_SUCCESS;
 }
 
@@ -5049,7 +5066,7 @@ int32_t tSerializeBlockDistInfo(void* buf, int32_t bufLen, const STableBlockDist
   if (tEncodeU32(&encoder, pInfo->rowSize) < 0) return -1;
 
   if (tEncodeU16(&encoder, pInfo->numOfFiles) < 0) return -1;
-  if (tEncodeU32(&encoder, pInfo->rowSize) < 0) return -1;
+  if (tEncodeU32(&encoder, pInfo->numOfBlocks) < 0) return -1;
   if (tEncodeU32(&encoder, pInfo->numOfTables) < 0) return -1;
 
   if (tEncodeU64(&encoder, pInfo->totalSize) < 0) return -1;
@@ -5080,7 +5097,7 @@ int32_t tDeserializeBlockDistInfo(void* buf, int32_t bufLen, STableBlockDistInfo
   if (tDecodeU32(&decoder, &pInfo->rowSize) < 0) return -1;
 
   if (tDecodeU16(&decoder, &pInfo->numOfFiles) < 0) return -1;
-  if (tDecodeU32(&decoder, &pInfo->rowSize) < 0) return -1;
+  if (tDecodeU32(&decoder, &pInfo->numOfBlocks) < 0) return -1;
   if (tDecodeU32(&decoder, &pInfo->numOfTables) < 0) return -1;
 
   if (tDecodeU64(&decoder, &pInfo->totalSize) < 0) return -1;
@@ -5102,32 +5119,29 @@ int32_t tDeserializeBlockDistInfo(void* buf, int32_t bufLen, STableBlockDistInfo
 
 int32_t blockDistFinalize(SqlFunctionCtx* pCtx, SSDataBlock* pBlock) {
   SResultRowEntryInfo* pResInfo = GET_RES_INFO(pCtx);
-  char*                pData = GET_ROWCELL_INTERBUF(pResInfo);
+  STableBlockDistInfo* pData = GET_ROWCELL_INTERBUF(pResInfo);
 
   SColumnInfoData* pColInfo = taosArrayGet(pBlock->pDataBlock, 0);
 
   int32_t row = 0;
-
-  STableBlockDistInfo info = {0};
-  tDeserializeBlockDistInfo(varDataVal(pData), varDataLen(pData), &info);
-
   char    st[256] = {0};
+  double  totalRawSize = pData->totalRows * pData->rowSize;
   int32_t len =
-      sprintf(st + VARSTR_HEADER_SIZE, "Blocks=[%d] Size=[%.3fKb] Average_Block_size=[%.3fKb] Compression_Ratio=[%.3f]",
-              info.numOfBlocks, info.totalSize / 1024.0, info.totalSize / (info.numOfBlocks * 1024.0),
-              info.totalSize / (info.totalRows * info.rowSize * 1.0));
+      sprintf(st + VARSTR_HEADER_SIZE, "Total_Blocks=[%d] Total_Size=[%.2f Kb] Average_size=[%.2f Kb] Compression_Ratio=[%.2f %c]",
+              pData->numOfBlocks, pData->totalSize / 1024.0, ((double)pData->totalSize) / pData->numOfBlocks,
+              pData->totalSize * 100 / totalRawSize, '%');
 
   varDataSetLen(st, len);
   colDataAppend(pColInfo, row++, st, false);
 
-  len = sprintf(st + VARSTR_HEADER_SIZE, "Total_Rows=[%ld] MinRows=[%d] MaxRows=[%d] Averge_Rows=[%ld] Inmem_Rows=[%d]",
-                info.totalRows, info.minRows, info.maxRows, info.totalRows / info.numOfBlocks, info.numOfInmemRows);
+  len = sprintf(st + VARSTR_HEADER_SIZE, "Total_Rows=[%"PRId64"] Inmem_Rows=[%d] MinRows=[%d] MaxRows=[%d] Average_Rows=[%"PRId64"]",
+                pData->totalRows, pData->numOfInmemRows, pData->minRows, pData->maxRows, pData->totalRows / pData->numOfBlocks);
 
   varDataSetLen(st, len);
   colDataAppend(pColInfo, row++, st, false);
 
-  len = sprintf(st + VARSTR_HEADER_SIZE, "Total_Tables=[%d] Total_Files=[%d] Total_Vgroups=[%d]", info.numOfTables,
-                info.numOfFiles, 0);
+  len = sprintf(st + VARSTR_HEADER_SIZE, "Total_Tables=[%d] Total_Files=[%d] Total_Vgroups=[%d]", pData->numOfTables,
+                pData->numOfFiles, 0);
 
   varDataSetLen(st, len);
   colDataAppend(pColInfo, row++, st, false);
@@ -5139,40 +5153,56 @@ int32_t blockDistFinalize(SqlFunctionCtx* pCtx, SSDataBlock* pBlock) {
 
   int32_t maxVal = 0;
   int32_t minVal = INT32_MAX;
-  for (int32_t i = 0; i < sizeof(info.blockRowsHisto) / sizeof(info.blockRowsHisto[0]); ++i) {
-    if (maxVal < info.blockRowsHisto[i]) {
-      maxVal = info.blockRowsHisto[i];
+  for (int32_t i = 0; i < tListLen(pData->blockRowsHisto); ++i) {
+    if (maxVal < pData->blockRowsHisto[i]) {
+      maxVal = pData->blockRowsHisto[i];
     }
 
-    if (minVal > info.blockRowsHisto[i]) {
-      minVal = info.blockRowsHisto[i];
+    if (minVal > pData->blockRowsHisto[i]) {
+      minVal = pData->blockRowsHisto[i];
     }
   }
 
   int32_t delta = maxVal - minVal;
   int32_t step = delta / 50;
+  if (step == 0) {
+    step = 1;
+  }
+
+  int32_t numOfBuckets = sizeof(pData->blockRowsHisto) / sizeof(pData->blockRowsHisto[0]);
+  int32_t bucketRange = (pData->maxRows - pData->minRows) / numOfBuckets;
 
-  int32_t numOfBuckets = sizeof(info.blockRowsHisto) / sizeof(info.blockRowsHisto[0]);
-  int32_t bucketRange = (info.maxRows - info.minRows) / numOfBuckets;
+  bool singleModel = false;
+  if (bucketRange == 0) {
+    singleModel = true;
+    step = 20;
+    bucketRange = (pData->defMaxRows - pData->defMinRows) / numOfBuckets;
+  }
 
-  for (int32_t i = 0; i < 20; ++i) {
-    len += sprintf(st + VARSTR_HEADER_SIZE, "%04d |", info.defMinRows + bucketRange * (i + 1));
+  for (int32_t i = 0; i < tListLen(pData->blockRowsHisto); ++i) {
+    len = sprintf(st + VARSTR_HEADER_SIZE, "%04d |", pData->defMinRows + bucketRange * (i + 1));
+
+    int32_t num = 0;
+    if (singleModel && pData->blockRowsHisto[i] > 0) {
+      num = 20;
+    } else {
+      num = (pData->blockRowsHisto[i] + step - 1) / step;
+    }
 
-    int32_t num = (info.blockRowsHisto[i] + step - 1) / step;
     for (int32_t j = 0; j < num; ++j) {
       int32_t x = sprintf(st + VARSTR_HEADER_SIZE + len, "%c", '|');
       len += x;
     }
 
-    double v = info.blockRowsHisto[i] * 100.0 / info.numOfBlocks;
-    len += sprintf(st + VARSTR_HEADER_SIZE + len, "  %d (%.3f%c)", info.blockRowsHisto[i], v, '%');
+    double v = pData->blockRowsHisto[i] * 100.0 / pData->numOfBlocks;
+    len += sprintf(st + VARSTR_HEADER_SIZE + len, "  %d (%.2f%c)", pData->blockRowsHisto[i], v, '%');
     printf("%s\n", st);
 
     varDataSetLen(st, len);
     colDataAppend(pColInfo, row++, st, false);
   }
 
-  return row;
+  return TSDB_CODE_SUCCESS;
 }
 
 typedef struct SDerivInfo {

source/libs/parser/src/parAstParser.c

@@ -419,6 +419,21 @@ static int32_t collectMetaKeyFromDelete(SCollectMetaKeyCxt* pCxt, SDeleteStmt* p
   return collectMetaKeyFromRealTableImpl(pCxt, (SRealTableNode*)pStmt->pFromTable, AUTH_TYPE_WRITE);
 }
 
+static int32_t collectMetaKeyFromShowBlockDist(SCollectMetaKeyCxt* pCxt, SShowTableDistributedStmt* pStmt) {
+  SName name = {.type = TSDB_TABLE_NAME_T, .acctId = pCxt->pParseCxt->acctId};
+  strcpy(name.dbname, pStmt->dbName);
+  strcpy(name.tname, pStmt->tableName);
+  int32_t code = catalogRemoveTableMeta(pCxt->pParseCxt->pCatalog, &name);
+  if (TSDB_CODE_SUCCESS == code) {
+    code = reserveTableMetaInCache(pCxt->pParseCxt->acctId, pStmt->dbName, pStmt->tableName, pCxt->pMetaCache);
+  }
+
+  if (TSDB_CODE_SUCCESS == code) {
+    code = reserveTableVgroupInCache(pCxt->pParseCxt->acctId, pStmt->dbName, pStmt->tableName, pCxt->pMetaCache);
+  }
+  return code;
+}
+
 static int32_t collectMetaKeyFromQuery(SCollectMetaKeyCxt* pCxt, SNode* pStmt) {
   pCxt->pStmt = pStmt;
   switch (nodeType(pStmt)) {
@@ -497,6 +512,8 @@ static int32_t collectMetaKeyFromQuery(SCollectMetaKeyCxt* pCxt, SNode* pStmt) {
       return collectMetaKeyFromShowTransactions(pCxt, (SShowStmt*)pStmt);
     case QUERY_NODE_DELETE_STMT:
       return collectMetaKeyFromDelete(pCxt, (SDeleteStmt*)pStmt);
+    case QUERY_NODE_SHOW_TABLE_DISTRIBUTED_STMT:
+      return collectMetaKeyFromShowBlockDist(pCxt, (SShowTableDistributedStmt*)pStmt);
     default:
       break;
   }