fix: select tags and set tag scan execution mode

include/common/ttokendef.h

@@ -16,6 +16,7 @@
 #ifndef _TD_COMMON_TOKEN_H_
 #define _TD_COMMON_TOKEN_H_
 
+
 #define TK_OR                               1
 #define TK_AND                              2
 #define TK_UNION                            3
@@ -354,7 +355,6 @@
 #define TK_VIEW                           336
 #define TK_WAL                            337
 
-
 #define TK_NK_SPACE   600
 #define TK_NK_COMMENT 601
 #define TK_NK_ILLEGAL 602

source/libs/parser/inc/parAst.h

@@ -143,6 +143,7 @@ SNode* addRangeClause(SAstCreateContext* pCxt, SNode* pStmt, SNode* pRange);
 SNode* addEveryClause(SAstCreateContext* pCxt, SNode* pStmt, SNode* pEvery);
 SNode* addFillClause(SAstCreateContext* pCxt, SNode* pStmt, SNode* pFill);
 SNode* createSelectStmt(SAstCreateContext* pCxt, bool isDistinct, SNodeList* pProjectionList, SNode* pTable);
+SNode* setSelectStmtTagMode(SAstCreateContext* pCxt, SNode* pStmt, bool bSelectTags);
 SNode* createSetOperator(SAstCreateContext* pCxt, ESetOperatorType type, SNode* pLeft, SNode* pRight);
 
 SDataType createDataType(uint8_t type);

source/libs/parser/inc/sql.y

@@ -1013,7 +1013,7 @@ query_specification(A) ::=
   where_clause_opt(E) partition_by_clause_opt(F) range_opt(J) every_opt(K)
   fill_opt(L) twindow_clause_opt(G) group_by_clause_opt(H) having_clause_opt(I).  {
                                                                                     A = createSelectStmt(pCxt, B, C, D);
-                                                                                    A = setSelectStmtTagMode(pCtxt, A, M);
+                                                                                    A = setSelectStmtTagMode(pCxt, A, M);
                                                                                     A = addWhereClause(pCxt, A, E);
                                                                                     A = addPartitionByClause(pCxt, A, F);
                                                                                     A = addWindowClauseClause(pCxt, A, G);

source/libs/parser/src/parAstCreater.c

@@ -852,6 +852,13 @@ SNode* createSelectStmt(SAstCreateContext* pCxt, bool isDistinct, SNodeList* pPr
   return select;  
 }
 
+SNode* setSelectStmtTagMode(SAstCreateContext* pCxt, SNode* pStmt, bool bSelectTags) {
+  if (QUERY_NODE_SELECT_STMT == nodeType(pStmt)) {
+    ((SSelectStmt*)pStmt)->tagScan = bSelectTags;
+  }
+  return pStmt;
+}
+
 static void setSubquery(SNode* pStmt) {
   if (QUERY_NODE_SELECT_STMT == nodeType(pStmt)) {
     ((SSelectStmt*)pStmt)->isSubquery = true;

source/libs/planner/src/planLogicCreater.c

@@ -14,7 +14,7 @@
  */
 
 #include "planInt.h"
-
+#include "filter.h"
 #include "functionMgt.h"
 
 typedef struct SLogicPlanContext {
@@ -344,6 +344,45 @@ static int32_t makeScanLogicNode(SLogicPlanContext* pCxt, SRealTableNode* pRealT
 
 static bool needScanDefaultCol(EScanType scanType) { return SCAN_TYPE_TABLE_COUNT != scanType; }
 
+static EDealRes tagScanNodeHasTbnameFunc(SNode* pNode, void* pContext) {
+  if (QUERY_NODE_COLUMN == nodeType(pNode)) {
+    if (COLUMN_TYPE_TBNAME == ((SColumnNode*)pNode)->colType) {
+      *(bool*)pContext = true;
+      return DEAL_RES_END;
+    }
+  }
+  return DEAL_RES_CONTINUE;
+}
+
+static bool tagScanNodeListHasTbname(SNodeList* pCols) {
+  bool hasTbname = false;
+  nodesWalkExprs(pCols, tagScanNodeHasTbnameFunc, &hasTbname);
+  return hasTbname;
+}
+
+static bool tagScanNodeHasTbname(SNode* pKeys) {
+  bool hasTbname = false;
+  nodesWalkExpr(pKeys, tagScanNodeHasTbnameFunc, &hasTbname);
+  return hasTbname;
+}
+
+static int32_t setTagScanOnlyMetaCtbIdx(SScanLogicNode* pScan) {
+  SNode* pCond = nodesCloneNode(pScan->node.pConditions);
+  SNode* pTagCond = NULL;
+  SNode* pTagIndexCond = NULL;
+  bool bOnlyMetaCtbIdx = false;
+  filterPartitionCond(&pCond, NULL, &pTagIndexCond, &pTagCond, NULL);
+  if (pTagIndexCond || tagScanNodeListHasTbname(pScan->pScanPseudoCols) || tagScanNodeHasTbname(pTagCond)) {
+    bOnlyMetaCtbIdx = false;
+  } else {
+    bOnlyMetaCtbIdx = true;
+  }
+  nodesDestroyNode(pCond);
+  nodesDestroyNode(pTagIndexCond);
+  nodesDestroyNode(pTagCond);
+  return TSDB_CODE_SUCCESS;
+}
+
 static int32_t createScanLogicNode(SLogicPlanContext* pCxt, SSelectStmt* pSelect, SRealTableNode* pRealTable,
                                    SLogicNode** pLogicNode) {
   SScanLogicNode* pScan = NULL;
@@ -411,6 +450,10 @@ static int32_t createScanLogicNode(SLogicPlanContext* pCxt, SSelectStmt* pSelect
     code = createColumnByRewriteExprs(pScan->pScanPseudoCols, &pScan->node.pTargets);
   }
 
+  if (pSelect->tagScan) {
+    code = setTagScanOnlyMetaCtbIdx(pScan);
+  }
+
   if (TSDB_CODE_SUCCESS == code) {
     *pLogicNode = (SLogicNode*)pScan;
   } else {