enh: query get dbcfg optimization

include/libs/function/functionMgt.h

@@ -176,7 +176,8 @@ int32_t fmGetFuncInfo(SFunctionNode* pFunc, char* pMsg, int32_t msgLen);
 
 EFuncReturnRows fmGetFuncReturnRows(SFunctionNode* pFunc);
 
-bool fmIsBuiltinFunc(const char* pFunc);
+bool          fmIsBuiltinFunc(const char* pFunc);
+EFunctionType fmGetFuncType(const char* pFunc);
 
 bool fmIsAggFunc(int32_t funcId);
 bool fmIsScalarFunc(int32_t funcId);

source/libs/function/src/functionMgt.c

@@ -101,6 +101,14 @@ bool fmIsBuiltinFunc(const char* pFunc) {
   return NULL != taosHashGet(gFunMgtService.pFuncNameHashTable, pFunc, strlen(pFunc));
 }
 
+EFunctionType fmGetFuncType(const char* pFunc) {
+  void* pVal = taosHashGet(gFunMgtService.pFuncNameHashTable, pFunc, strlen(pFunc));
+  if (NULL != pVal) {
+    return funcMgtBuiltins[*(int32_t*)pVal].type;
+  }
+  return FUNCTION_TYPE_UDF;
+}
+
 EFuncDataRequired fmFuncDataRequired(SFunctionNode* pFunc, STimeWindow* pTimeWindow) {
   if (fmIsUserDefinedFunc(pFunc->funcId) || pFunc->funcId < 0 || pFunc->funcId >= funcMgtBuiltinsNum) {
     return FUNC_DATA_REQUIRED_DATA_LOAD;

source/libs/parser/src/parAstParser.c

@@ -97,16 +97,23 @@ typedef struct SCollectMetaKeyCxt {
 
 typedef struct SCollectMetaKeyFromExprCxt {
   SCollectMetaKeyCxt* pComCxt;
+  bool                hasLastRow;
   int32_t             errCode;
 } SCollectMetaKeyFromExprCxt;
 
 static int32_t collectMetaKeyFromQuery(SCollectMetaKeyCxt* pCxt, SNode* pStmt);
 
 static EDealRes collectMetaKeyFromFunction(SCollectMetaKeyFromExprCxt* pCxt, SFunctionNode* pFunc) {
-  if (fmIsBuiltinFunc(pFunc->functionName)) {
-    return DEAL_RES_CONTINUE;
+  switch (fmGetFuncType(pFunc->functionName)) {
+    case FUNCTION_TYPE_LAST_ROW:
+      pCxt->hasLastRow = true;
+      break;
+    case FUNCTION_TYPE_UDF:
+      pCxt->errCode = reserveUdfInCache(pFunc->functionName, pCxt->pComCxt->pMetaCache);
+      break;
+    default:
+      break;
   }
-  pCxt->errCode = reserveUdfInCache(pFunc->functionName, pCxt->pComCxt->pMetaCache);
   return TSDB_CODE_SUCCESS == pCxt->errCode ? DEAL_RES_CONTINUE : DEAL_RES_ERROR;
 }
 
@@ -136,9 +143,6 @@ static int32_t collectMetaKeyFromRealTableImpl(SCollectMetaKeyCxt* pCxt, const c
   if (TSDB_CODE_SUCCESS == code && (0 == strcmp(pTable, TSDB_INS_TABLE_DNODE_VARIABLES))) {
     code = reserveDnodeRequiredInCache(pCxt->pMetaCache);
   }
-  if (TSDB_CODE_SUCCESS == code) {
-    code = reserveDbCfgInCache(pCxt->pParseCxt->acctId, pDb, pCxt->pMetaCache);
-  }
   return code;
 }
 
@@ -185,9 +189,19 @@ static int32_t collectMetaKeyFromSetOperator(SCollectMetaKeyCxt* pCxt, SSetOpera
   return code;
 }
 
+static int32_t reserveDbCfgForLastRow(SCollectMetaKeyCxt* pCxt, SNode* pTable) {
+  if (NULL == pTable || QUERY_NODE_REAL_TABLE != nodeType(pTable)) {
+    return TSDB_CODE_SUCCESS;
+  }
+  return reserveDbCfgInCache(pCxt->pParseCxt->acctId, ((SRealTableNode*)pTable)->table.dbName, pCxt->pMetaCache);
+}
+
 static int32_t collectMetaKeyFromSelect(SCollectMetaKeyCxt* pCxt, SSelectStmt* pStmt) {
-  SCollectMetaKeyFromExprCxt cxt = {.pComCxt = pCxt, .errCode = TSDB_CODE_SUCCESS};
+  SCollectMetaKeyFromExprCxt cxt = {.pComCxt = pCxt, .hasLastRow = false, .errCode = TSDB_CODE_SUCCESS};
   nodesWalkSelectStmt(pStmt, SQL_CLAUSE_FROM, collectMetaKeyFromExprImpl, &cxt);
+  if (TSDB_CODE_SUCCESS == cxt.errCode && cxt.hasLastRow) {
+    cxt.errCode = reserveDbCfgForLastRow(pCxt, pStmt->pFromTable);
+  }
   return cxt.errCode;
 }
 

source/libs/parser/src/parTranslater.c

@@ -2160,15 +2160,16 @@ static int32_t setTableIndex(STranslateContext* pCxt, SName* pName, SRealTableNo
   return TSDB_CODE_SUCCESS;
 }
 
-static int32_t setTableCacheLastMode(STranslateContext* pCxt, SName* pName, SRealTableNode* pRealTable) {
-  if (TSDB_SYSTEM_TABLE == pRealTable->pMeta->tableType) {
+static int32_t setTableCacheLastMode(STranslateContext* pCxt, SSelectStmt* pSelect) {
+  if (!pSelect->hasLastRowFunc || QUERY_NODE_REAL_TABLE != nodeType(pSelect->pFromTable)) {
     return TSDB_CODE_SUCCESS;
   }
 
-  SDbCfgInfo dbCfg = {0};
-  int32_t    code = getDBCfg(pCxt, pRealTable->table.dbName, &dbCfg);
+  SRealTableNode* pTable = (SRealTableNode*)pSelect->pFromTable;
+  SDbCfgInfo      dbCfg = {0};
+  int32_t         code = getDBCfg(pCxt, pTable->table.dbName, &dbCfg);
   if (TSDB_CODE_SUCCESS == code) {
-    pRealTable->cacheLastMode = dbCfg.cacheLast;
+    pTable->cacheLastMode = dbCfg.cacheLast;
   }
   return code;
 }
@@ -2192,9 +2193,6 @@ static int32_t translateTable(STranslateContext* pCxt, SNode* pTable) {
         if (TSDB_CODE_SUCCESS == code) {
           code = setTableIndex(pCxt, &name, pRealTable);
         }
-        if (TSDB_CODE_SUCCESS == code) {
-          code = setTableCacheLastMode(pCxt, &name, pRealTable);
-        }
       }
       if (TSDB_CODE_SUCCESS == code) {
         pRealTable->table.precision = pRealTable->pMeta->tableInfo.precision;
@@ -2273,10 +2271,14 @@ static SNode* createMultiResFunc(SFunctionNode* pSrcFunc, SExprNode* pExpr) {
   if (QUERY_NODE_COLUMN == nodeType(pExpr)) {
     SColumnNode* pCol = (SColumnNode*)pExpr;
     len = snprintf(buf, sizeof(buf), "%s(%s.%s)", pSrcFunc->functionName, pCol->tableAlias, pCol->colName);
+    strncpy(pFunc->node.aliasName, buf, TMIN(len, sizeof(pFunc->node.aliasName) - 1));
+    len = snprintf(buf, sizeof(buf), "%s(%s)", pSrcFunc->functionName, pCol->colName);
+    strncpy(pFunc->node.userAlias, buf, TMIN(len, sizeof(pFunc->node.userAlias) - 1));
   } else {
     len = snprintf(buf, sizeof(buf), "%s(%s)", pSrcFunc->functionName, pExpr->aliasName);
+    strncpy(pFunc->node.aliasName, buf, TMIN(len, sizeof(pFunc->node.aliasName) - 1));
+    strncpy(pFunc->node.userAlias, buf, TMIN(len, sizeof(pFunc->node.userAlias) - 1));
   }
-  strncpy(pFunc->node.aliasName, buf, TMIN(len, sizeof(pFunc->node.aliasName) - 1));
 
   return (SNode*)pFunc;
 }
@@ -3140,6 +3142,9 @@ static int32_t translateSelectFrom(STranslateContext* pCxt, SSelectStmt* pSelect
   if (TSDB_CODE_SUCCESS == code) {
     code = replaceOrderByAliasForSelect(pCxt, pSelect);
   }
+  if (TSDB_CODE_SUCCESS == code) {
+    code = setTableCacheLastMode(pCxt, pSelect);
+  }
   return code;
 }