[td-225]fix bug found by regression test.

src/query/src/qExecutor.c

@@ -4145,8 +4145,8 @@ static SFillColInfo* createFillColInfo(SExprInfo* pExpr, int32_t numOfOutput, in
   return pFillCol;
 }
 
-int32_t doInitQInfo(SQInfo* pQInfo, STSBuf* pTsBuf, void* tsdb, void* sourceOptr, int32_t tbScanner,
-                    SArray* pOperator, void* param) {
+int32_t doInitQInfo(SQInfo* pQInfo, STSBuf* pTsBuf, void* tsdb, void* sourceOptr, int32_t tbScanner, SArray* pOperator,
+    void* param) {
   SQueryRuntimeEnv *pRuntimeEnv = &pQInfo->runtimeEnv;
 
   SQueryAttr *pQueryAttr = pQInfo->runtimeEnv.pQueryAttr;

src/tsdb/src/tsdbRead.c

@@ -343,6 +343,15 @@ static SArray* createCheckInfoFromCheckInfo(STableCheckInfo* pCheckInfo, TSKEY s
   return pNew;
 }
 
+static bool emptyQueryTimewindow(STsdbQueryHandle* pQueryHandle) {
+  assert(pQueryHandle != NULL);
+
+  STimeWindow* w = &pQueryHandle->window;
+  bool asc = ASCENDING_TRAVERSE(pQueryHandle->order);
+
+  return ((asc && w->skey > w->ekey) || (!asc && w->ekey > w->skey));
+}
+
 // Update the query time window according to the data time to live(TTL) information, in order to avoid to return
 // the expired data to client, even it is queried already.
 static int64_t getEarliestValidTimestamp(STsdbRepo* pTsdb) {
@@ -355,23 +364,27 @@ static int64_t getEarliestValidTimestamp(STsdbRepo* pTsdb) {
 static void setQueryTimewindow(STsdbQueryHandle* pQueryHandle, STsdbQueryCond* pCond) {
   pQueryHandle->window = pCond->twindow;
 
+  bool    updateTs = false;
   int64_t startTs = getEarliestValidTimestamp(pQueryHandle->pTsdb);
   if (ASCENDING_TRAVERSE(pQueryHandle->order)) {
     if (startTs > pQueryHandle->window.skey) {
       pQueryHandle->window.skey = startTs;
+      pCond->twindow.skey = startTs;
+      updateTs = true;
     }
-
-    assert(pQueryHandle->window.skey <= pQueryHandle->window.ekey);
   } else {
     if (startTs > pQueryHandle->window.ekey) {
       pQueryHandle->window.ekey = startTs;
+      pCond->twindow.ekey = startTs;
+      updateTs = true;
     }
-
-    assert(pQueryHandle->window.skey >= pQueryHandle->window.ekey);
   }
 
-  tsdbDebug("%p update the query time window, old:%"PRId64" - %"PRId64", new:%"PRId64" - %"PRId64 ", 0x%"PRIx64,
-      pQueryHandle, pCond->twindow.skey, pCond->twindow.ekey, pQueryHandle->window.skey, pQueryHandle->window.ekey, pQueryHandle->qId);
+  if (updateTs) {
+    tsdbDebug("%p update the query time window, old:%" PRId64 " - %" PRId64 ", new:%" PRId64 " - %" PRId64
+              ", 0x%" PRIx64, pQueryHandle, pCond->twindow.skey, pCond->twindow.ekey, pQueryHandle->window.skey,
+              pQueryHandle->window.ekey, pQueryHandle->qId);
+  }
 }
 
 static STsdbQueryHandle* tsdbQueryTablesImpl(STsdbRepo* tsdb, STsdbQueryCond* pCond, uint64_t qId, SMemRef* pMemRef) {
@@ -456,6 +469,9 @@ static STsdbQueryHandle* tsdbQueryTablesImpl(STsdbRepo* tsdb, STsdbQueryCond* pC
 
 TsdbQueryHandleT* tsdbQueryTables(STsdbRepo* tsdb, STsdbQueryCond* pCond, STableGroupInfo* groupList, uint64_t qId, SMemRef* pRef) {
   STsdbQueryHandle* pQueryHandle = tsdbQueryTablesImpl(tsdb, pCond, qId, pRef);
+  if (emptyQueryTimewindow(pQueryHandle)) {
+    return (TsdbQueryHandleT*) pQueryHandle;
+  }
 
   STsdbMeta* pMeta = tsdbGetMeta(tsdb);
   assert(pMeta != NULL);
@@ -479,6 +495,15 @@ TsdbQueryHandleT* tsdbQueryTables(STsdbRepo* tsdb, STsdbQueryCond* pCond, STable
 void tsdbResetQueryHandle(TsdbQueryHandleT queryHandle, STsdbQueryCond *pCond) {
   STsdbQueryHandle* pQueryHandle = queryHandle;
 
+  if (emptyQueryTimewindow(pQueryHandle)) {
+    if (pCond->order != pQueryHandle->order) {
+      pQueryHandle->order = pCond->order;
+      SWAP(pQueryHandle->window.skey, pQueryHandle->window.ekey, int64_t);
+    }
+
+    return;
+  }
+
   pQueryHandle->order       = pCond->order;
   pQueryHandle->window      = pCond->twindow;
   pQueryHandle->type        = TSDB_QUERY_TYPE_ALL;
@@ -1204,8 +1229,9 @@ static int32_t handleDataMergeIfNeeded(STsdbQueryHandle* pQueryHandle, SBlock* p
 static int32_t loadFileDataBlock(STsdbQueryHandle* pQueryHandle, SBlock* pBlock, STableCheckInfo* pCheckInfo, bool* exists) {
   SQueryFilePos* cur = &pQueryHandle->cur;
   int32_t code = TSDB_CODE_SUCCESS;
+  bool asc = ASCENDING_TRAVERSE(pQueryHandle->order);
 
-  if (ASCENDING_TRAVERSE(pQueryHandle->order)) {
+  if (asc) {
     // query ended in/started from current block
     if (pQueryHandle->window.ekey < pBlock->keyLast || pCheckInfo->lastKey > pBlock->keyFirst) {
       if ((code = doLoadFileDataBlock(pQueryHandle, pBlock, pCheckInfo, cur->slot)) != TSDB_CODE_SUCCESS) {
@@ -1226,7 +1252,7 @@ static int32_t loadFileDataBlock(STsdbQueryHandle* pQueryHandle, SBlock* pBlock,
       assert(pCheckInfo->lastKey <= pBlock->keyLast);
       doMergeTwoLevelData(pQueryHandle, pCheckInfo, pBlock);
     } else {  // the whole block is loaded in to buffer
-      cur->pos = ASCENDING_TRAVERSE(pQueryHandle->order)? 0:(pBlock->numOfRows - 1);
+      cur->pos = asc? 0:(pBlock->numOfRows - 1);
       code = handleDataMergeIfNeeded(pQueryHandle, pBlock, pCheckInfo);
     }
   } else {  //desc order, query ended in current block
@@ -1246,7 +1272,7 @@ static int32_t loadFileDataBlock(STsdbQueryHandle* pQueryHandle, SBlock* pBlock,
       assert(pCheckInfo->lastKey >= pBlock->keyFirst);
       doMergeTwoLevelData(pQueryHandle, pCheckInfo, pBlock);
     } else {
-      cur->pos = ASCENDING_TRAVERSE(pQueryHandle->order)? 0:(pBlock->numOfRows-1);
+      cur->pos = asc? 0:(pBlock->numOfRows-1);
       code = handleDataMergeIfNeeded(pQueryHandle, pBlock, pCheckInfo);
     }
   }
@@ -2717,6 +2743,11 @@ static bool loadDataBlockFromTableSeq(STsdbQueryHandle* pQueryHandle) {
 bool tsdbNextDataBlock(TsdbQueryHandleT pHandle) {
   STsdbQueryHandle* pQueryHandle = (STsdbQueryHandle*) pHandle;
 
+  if (emptyQueryTimewindow(pQueryHandle)) {
+    tsdbDebug("%p query window not overlaps with the data set, no result returned, 0x%"PRIx64, pQueryHandle, pQueryHandle->qId);
+    return false;
+  }
+
   int64_t stime = taosGetTimestampUs();
   int64_t elapsedTime = stime;
 
@@ -3669,15 +3700,21 @@ void tsdbCleanupQueryHandle(TsdbQueryHandleT queryHandle) {
     return;
   }
 
-  pQueryHandle->pTableCheckInfo = destroyTableCheckInfo(pQueryHandle->pTableCheckInfo);
   pQueryHandle->pColumns = doFreeColumnInfoData(pQueryHandle->pColumns);
 
   taosArrayDestroy(pQueryHandle->defaultLoadColumn);
   tfree(pQueryHandle->pDataBlockInfo);
   tfree(pQueryHandle->statis);
 
-  // todo check error
-  tsdbMayUnTakeMemSnapshot(pQueryHandle);
+  if (!emptyQueryTimewindow(pQueryHandle)) {
+    tsdbMayUnTakeMemSnapshot(pQueryHandle);
+  } else {
+    assert(pQueryHandle->pTableCheckInfo == NULL);
+  }
+
+  if (pQueryHandle->pTableCheckInfo != NULL) {
+    pQueryHandle->pTableCheckInfo = destroyTableCheckInfo(pQueryHandle->pTableCheckInfo);
+  }
 
   tsdbDestroyReadH(&pQueryHandle->rhelper);
 

tests/script/general/parser/single_row_in_tb_query.sim

@@ -193,3 +193,7 @@ endi
 if $data04 != 1 then
   return -1
 endi
+
+print ===============>safty check TD-4927
+sql select first(ts, c1) from sr_stb where ts<1 group by t1;
+sql select first(ts, c1) from sr_stb where ts>0 and ts<1;
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