enhance: skip data blocks with the merge limit ts when create initial source

source/libs/executor/src/tsort.c

@@ -51,6 +51,7 @@ struct SSortHandle {
   uint32_t         tmpRowIdx;
 
   int64_t          mergeLimit;
+  int64_t          currMergeLimitTs;          
 
   int32_t           sourceId;
   SSDataBlock*      pDataBlock;
@@ -921,7 +922,8 @@ static int32_t sortBlocksToExtSource(SSortHandle* pHandle, SArray* aBlk, SBlockO
   int32_t nMergedRows = 0;
   bool mergeLimitReached = false;
   size_t blkPgSz = pgHeaderSz;
-
+  int64_t lastPageBufTs = (order->order == TSDB_ORDER_ASC) ? INT64_MAX : INT64_MIN;
+  int64_t currTs = (order->order == TSDB_ORDER_ASC) ? INT64_MAX : INT64_MIN;
   while (nRows < totalRows) {
     int32_t minIdx = tMergeTreeGetChosenIndex(pTree);
     SSDataBlock* minBlk = taosArrayGetP(aBlk, minIdx);
@@ -929,14 +931,21 @@ static int32_t sortBlocksToExtSource(SSortHandle* pHandle, SArray* aBlk, SBlockO
     int32_t bufInc = getPageBufIncForRow(minBlk, minRow, pHandle->pDataBlock->info.rows);
 
     if (blkPgSz <= pHandle->pageSize && blkPgSz + bufInc > pHandle->pageSize) {
+        SColumnInfoData* tsCol = taosArrayGet(pHandle->pDataBlock->pDataBlock, order->slotId);
+        lastPageBufTs = ((int64_t*)tsCol->pData)[pHandle->pDataBlock->info.rows - 1];
         appendDataBlockToPageBuf(pHandle, pHandle->pDataBlock, aPgId);
         nMergedRows += pHandle->pDataBlock->info.rows;
 
         blockDataCleanup(pHandle->pDataBlock);
         blkPgSz = pgHeaderSz;
         bufInc = getPageBufIncForRow(minBlk, minRow, 0);
+        
         if ((pHandle->mergeLimit != -1) && (nMergedRows >= pHandle->mergeLimit)) {
           mergeLimitReached = true;
+          if ((lastPageBufTs < pHandle->currMergeLimitTs && order->order == TSDB_ORDER_ASC) ||
+              (lastPageBufTs > pHandle->currMergeLimitTs && order->order == TSDB_ORDER_DESC)) {
+                pHandle->currMergeLimitTs = lastPageBufTs;
+          }
           break;
         }        
     }
@@ -955,8 +964,17 @@ static int32_t sortBlocksToExtSource(SSortHandle* pHandle, SArray* aBlk, SBlockO
   }
   if (pHandle->pDataBlock->info.rows > 0) {
     if (!mergeLimitReached) {
+      SColumnInfoData* tsCol = taosArrayGet(pHandle->pDataBlock->pDataBlock, order->slotId);
+      lastPageBufTs = ((int64_t*)tsCol->pData)[pHandle->pDataBlock->info.rows - 1];
       appendDataBlockToPageBuf(pHandle, pHandle->pDataBlock, aPgId);
       nMergedRows += pHandle->pDataBlock->info.rows;
+      if ((pHandle->mergeLimit != -1) && (nMergedRows >= pHandle->mergeLimit)) {
+          mergeLimitReached = true;
+          if ((lastPageBufTs < pHandle->currMergeLimitTs && order->order == TSDB_ORDER_ASC) ||
+              (lastPageBufTs > pHandle->currMergeLimitTs && order->order == TSDB_ORDER_DESC)) {
+                pHandle->currMergeLimitTs = lastPageBufTs;
+          }
+      }
     }
     blockDataCleanup(pHandle->pDataBlock);
   }
@@ -982,11 +1000,24 @@ static int32_t createBlocksMergeSortInitialSources(SSortHandle* pHandle) {
   SSortSource* pSrc = taosArrayGetP(pHandle->pOrderedSource, 0);
   int32_t      szSort = 0;
 
+  if (pOrder->order == TSDB_ORDER_ASC) {
+    pHandle->currMergeLimitTs = INT64_MAX;
+  } else {
+    pHandle->currMergeLimitTs = INT64_MIN;
+  }
+
   SArray* aBlkSort = taosArrayInit(8, POINTER_BYTES);
   SSHashObj* mUidBlk = tSimpleHashInit(64, taosGetDefaultHashFunction(TSDB_DATA_TYPE_UBIGINT));
   while (1) {
     SSDataBlock* pBlk = pHandle->fetchfp(pSrc->param);
-
+    if (pBlk != NULL) {
+      SColumnInfoData* tsCol = taosArrayGet(pBlk->pDataBlock, pOrder->slotId);
+      int64_t firstRowTs = *(int64_t*)tsCol->pData;
+      if ((pOrder->order == TSDB_ORDER_ASC && firstRowTs > pHandle->currMergeLimitTs)  ||
+          (pOrder->order == TSDB_ORDER_DESC && firstRowTs < pHandle->currMergeLimitTs)) {
+            continue;
+          }
+    }
     if (pBlk != NULL) {
       szSort += blockDataGetSize(pBlk);