constant condition optimize

include/libs/nodes/querynodes.h

@@ -238,6 +238,7 @@ typedef struct SSelectStmt {
   SNode* pSlimit;
   char stmtName[TSDB_TABLE_NAME_LEN];
   uint8_t precision;
+  bool isEmptyResult;
 } SSelectStmt;
 
 typedef enum ESetOperatorType {

include/libs/parser/parser.h

@@ -44,8 +44,15 @@ typedef struct SCmdMsgInfo {
   void* pExtension;  // todo remove it soon
 } SCmdMsgInfo;
 
+typedef enum EQueryExecMode {
+  QUERY_EXEC_MODE_LOCAL = 1,
+  QUERY_EXEC_MODE_RPC,
+  QUERY_EXEC_MODE_SCHEDULE,
+  QUERY_EXEC_MODE_EMPTY_RESULT
+} EQueryExecMode;
+
 typedef struct SQuery {
-  bool directRpc;
+  EQueryExecMode execMode;
   bool haveResultSet;
   SNode* pRoot;
   int32_t numOfResCols;
@@ -55,7 +62,6 @@ typedef struct SQuery {
   SArray* pDbList;
   SArray* pTableList;
   bool showRewrite;
-  bool localCmd;
 } SQuery;
 
 int32_t qParseQuerySql(SParseContext* pCxt, SQuery** pQuery);

source/client/src/clientImpl.c

@@ -281,22 +281,35 @@ int32_t scheduleQuery(SRequestObj* pRequest, SQueryPlan* pDag, SArray* pNodeList
 SRequestObj* execQueryImpl(STscObj* pTscObj, const char* sql, int sqlLen) {
   SRequestObj* pRequest = NULL;
   SQuery* pQuery = NULL;
-  int32_t code = 0;
   SArray* pNodeList = taosArrayInit(4, sizeof(struct SQueryNodeAddr));
 
-  CHECK_CODE_GOTO(buildRequest(pTscObj, sql, sqlLen, &pRequest), _return);
+  int32_t code = buildRequest(pTscObj, sql, sqlLen, &pRequest);
-  CHECK_CODE_GOTO(parseSql(pRequest, false, &pQuery), _return);
+  if (TSDB_CODE_SUCCESS == code) {
-
+    code = parseSql(pRequest, false, &pQuery);
-  if (pQuery->localCmd) {
+  }
-    CHECK_CODE_GOTO(execLocalCmd(pRequest, pQuery), _return);
+
-  } else if (pQuery->directRpc) {
+  if (TSDB_CODE_SUCCESS == code) {
-    CHECK_CODE_GOTO(execDdlQuery(pRequest, pQuery), _return);
+    switch (pQuery->execMode) {
-  } else {
+      case QUERY_EXEC_MODE_LOCAL:
-    CHECK_CODE_GOTO(getPlan(pRequest, pQuery, &pRequest->body.pDag, pNodeList), _return);
+        code = execLocalCmd(pRequest, pQuery);
-    CHECK_CODE_GOTO(scheduleQuery(pRequest, pRequest->body.pDag, pNodeList), _return);
+        break;
+      case QUERY_EXEC_MODE_RPC:
+        code = execDdlQuery(pRequest, pQuery);
+        break;
+      case QUERY_EXEC_MODE_SCHEDULE:
+        code = getPlan(pRequest, pQuery, &pRequest->body.pDag, pNodeList);
+        if (TSDB_CODE_SUCCESS == code) {
+          code = scheduleQuery(pRequest, pRequest->body.pDag, pNodeList);
+        }
+        break;
+      case QUERY_EXEC_MODE_EMPTY_RESULT:
+        pRequest->type = TSDB_SQL_RETRIEVE_EMPTY_RESULT;
+        break;
+      default:
+        break;
+    }
   }
 
-_return:
   taosArrayDestroy(pNodeList);
   qDestroyQuery(pQuery);
   if (NULL != pRequest && TSDB_CODE_SUCCESS != code) {

source/libs/parser/src/parCalcConst.c

@@ -149,22 +149,37 @@ static int32_t rewriteConditionForFromTable(SCalcConstContext* pCxt, SNode* pTab
   return pCxt->code;
 }
 
+static void rewriteConstCondition(SSelectStmt* pSelect, SNode** pCond) {
+  if (QUERY_NODE_VALUE != nodeType(*pCond)) {
+    return;
+  }
+  if (((SValueNode*)*pCond)->datum.b) {
+    nodesDestroyNode(*pCond);
+    *pCond = NULL;
+  } else {
+    pSelect->isEmptyResult = true;
+  }
+}
+
 static int32_t calcConstFromTable(SCalcConstContext* pCxt, SSelectStmt* pSelect) {
-  nodesRewriteExprPostOrder(&pSelect->pFromTable, calcConst, pCxt);
+  pCxt->code = rewriteConditionForFromTable(pCxt, pSelect->pFromTable);
   if (TSDB_CODE_SUCCESS == pCxt->code) {
-    pCxt->code = rewriteConditionForFromTable(pCxt, pSelect->pFromTable);
+    nodesRewriteExprPostOrder(&pSelect->pFromTable, calcConst, pCxt);
   }
   return pCxt->code;
 }
 
-static int32_t calcConstCondition(SCalcConstContext* pCxt, SNode** pCond) {
+static int32_t calcConstCondition(SCalcConstContext* pCxt, SSelectStmt* pSelect, SNode** pCond) {
   if (NULL == *pCond) {
     return TSDB_CODE_SUCCESS;
   }
 
-  nodesRewriteExprPostOrder(pCond, calcConst, pCxt);
+  pCxt->code = rewriteCondition(pCxt, pCond);
   if (TSDB_CODE_SUCCESS == pCxt->code) {
-    pCxt->code = rewriteCondition(pCxt, pCond);
+    nodesRewriteExprPostOrder(pCond, calcConst, pCxt);
+  }
+  if (TSDB_CODE_SUCCESS == pCxt->code) {
+    rewriteConstCondition(pSelect, pCond);
   }
   return pCxt->code;
 }
@@ -176,7 +191,7 @@ static int32_t calcConstSelect(SSelectStmt* pSelect) {
     cxt.code = calcConstFromTable(&cxt, pSelect);
   }
   if (TSDB_CODE_SUCCESS == cxt.code) {
-    cxt.code = calcConstCondition(&cxt, &pSelect->pWhere);
+    cxt.code = calcConstCondition(&cxt, pSelect, &pSelect->pWhere);
   }
   if (TSDB_CODE_SUCCESS == cxt.code) {
     nodesRewriteExprsPostOrder(pSelect->pPartitionByList, calcConst, &cxt);
@@ -188,7 +203,7 @@ static int32_t calcConstSelect(SSelectStmt* pSelect) {
     nodesRewriteExprsPostOrder(pSelect->pGroupByList, calcConst, &cxt);
   }
   if (TSDB_CODE_SUCCESS == cxt.code) {
-    cxt.code = calcConstCondition(&cxt, &pSelect->pHaving);
+    cxt.code = calcConstCondition(&cxt, pSelect, &pSelect->pHaving);
   }
   if (TSDB_CODE_SUCCESS == cxt.code) {
     nodesRewriteExprsPostOrder(pSelect->pOrderByList, calcConst, &cxt);
@@ -208,6 +223,22 @@ static int32_t calcConstQuery(SNode* pStmt) {
   return TSDB_CODE_SUCCESS;
 }
 
-int32_t calculateConstant(SParseContext* pParseCxt, SQuery* pQuery) {
+static bool isEmptyResultQuery(SNode* pStmt) {
-  return calcConstQuery(pQuery->pRoot);
+  switch (nodeType(pStmt)) {
+    case QUERY_NODE_SELECT_STMT:
+      return ((SSelectStmt*)pStmt)->isEmptyResult;    
+    case QUERY_NODE_EXPLAIN_STMT:
+      return isEmptyResultQuery(((SExplainStmt*)pStmt)->pQuery);
+    default:
+      break;
+  }
+  return false;
+}
+
+int32_t calculateConstant(SParseContext* pParseCxt, SQuery* pQuery) {
+  int32_t code = calcConstQuery(pQuery->pRoot);
+  if (TSDB_CODE_SUCCESS == code) {
+    pQuery->execMode = isEmptyResultQuery(pQuery->pRoot) ? QUERY_EXEC_MODE_EMPTY_RESULT : pQuery->execMode;
+  }
+  return code;
 }

source/libs/parser/src/parInsert.c

@@ -1084,7 +1084,7 @@ int32_t parseInsertSql(SParseContext* pContext, SQuery** pQuery) {
   if (NULL == *pQuery) {
     return TSDB_CODE_OUT_OF_MEMORY;
   }
-  (*pQuery)->directRpc = false;
+  (*pQuery)->execMode = QUERY_EXEC_MODE_SCHEDULE;
   (*pQuery)->haveResultSet = false;
   (*pQuery)->msgType = TDMT_VND_SUBMIT;
   (*pQuery)->pRoot = (SNode*)context.pOutput;

source/libs/parser/src/parTranslater.c

@@ -2923,21 +2923,23 @@ static int32_t setQuery(STranslateContext* pCxt, SQuery* pQuery) {
   switch (nodeType(pQuery->pRoot)) {
     case QUERY_NODE_SELECT_STMT:
     case QUERY_NODE_EXPLAIN_STMT:
+      pQuery->execMode = QUERY_EXEC_MODE_SCHEDULE;
       pQuery->haveResultSet = true;
       pQuery->msgType = TDMT_VND_QUERY;
       break;
     case QUERY_NODE_VNODE_MODIF_STMT:
+      pQuery->execMode = QUERY_EXEC_MODE_SCHEDULE;
       pQuery->msgType = TDMT_VND_CREATE_TABLE;
       break;
     case QUERY_NODE_DESCRIBE_STMT:
-      pQuery->localCmd = true;
+      pQuery->execMode = QUERY_EXEC_MODE_LOCAL;
       pQuery->haveResultSet = true;
       break;
     case QUERY_NODE_RESET_QUERY_CACHE_STMT:
-      pQuery->localCmd = true;
+      pQuery->execMode = QUERY_EXEC_MODE_LOCAL;
       break;
     default:
-      pQuery->directRpc = true;
+      pQuery->execMode = QUERY_EXEC_MODE_RPC;
       if (NULL != pCxt->pCmdMsg) {
         TSWAP(pQuery->pCmdMsg, pCxt->pCmdMsg, SCmdMsgInfo*);
         pQuery->msgType = pQuery->pCmdMsg->msgType;