TD-14396 explain parser and planner implement

include/common/ttokendef.h

@@ -138,55 +138,59 @@
 #define TK_INTERVAL                       120
 #define TK_TOPIC                          121
 #define TK_AS                             122
-#define TK_NK_BOOL                        123
+#define TK_EXPLAIN                        123
-#define TK_NULL                           124
+#define TK_ANALYZE                        124
-#define TK_NK_VARIABLE                    125
+#define TK_VERBOSE                        125
-#define TK_NK_UNDERLINE                   126
+#define TK_NK_BOOL                        126
-#define TK_ROWTS                          127
+#define TK_RATIO                          127
-#define TK_TBNAME                         128
+#define TK_NULL                           128
-#define TK_QSTARTTS                       129
+#define TK_NK_VARIABLE                    129
-#define TK_QENDTS                         130
+#define TK_NK_UNDERLINE                   130
-#define TK_WSTARTTS                       131
+#define TK_ROWTS                          131
-#define TK_WENDTS                         132
+#define TK_TBNAME                         132
-#define TK_WDURATION                      133
+#define TK_QSTARTTS                       133
-#define TK_BETWEEN                        134
+#define TK_QENDTS                         134
-#define TK_IS                             135
+#define TK_WSTARTTS                       135
-#define TK_NK_LT                          136
+#define TK_WENDTS                         136
-#define TK_NK_GT                          137
+#define TK_WDURATION                      137
-#define TK_NK_LE                          138
+#define TK_BETWEEN                        138
-#define TK_NK_GE                          139
+#define TK_IS                             139
-#define TK_NK_NE                          140
+#define TK_NK_LT                          140
-#define TK_MATCH                          141
+#define TK_NK_GT                          141
-#define TK_NMATCH                         142
+#define TK_NK_LE                          142
-#define TK_IN                             143
+#define TK_NK_GE                          143
-#define TK_JOIN                           144
+#define TK_NK_NE                          144
-#define TK_INNER                          145
+#define TK_MATCH                          145
-#define TK_SELECT                         146
+#define TK_NMATCH                         146
-#define TK_DISTINCT                       147
+#define TK_IN                             147
-#define TK_WHERE                          148
+#define TK_JOIN                           148
-#define TK_PARTITION                      149
+#define TK_INNER                          149
-#define TK_BY                             150
+#define TK_SELECT                         150
-#define TK_SESSION                        151
+#define TK_DISTINCT                       151
-#define TK_STATE_WINDOW                   152
+#define TK_WHERE                          152
-#define TK_SLIDING                        153
+#define TK_PARTITION                      153
-#define TK_FILL                           154
+#define TK_BY                             154
-#define TK_VALUE                          155
+#define TK_SESSION                        155
-#define TK_NONE                           156
+#define TK_STATE_WINDOW                   156
-#define TK_PREV                           157
+#define TK_SLIDING                        157
-#define TK_LINEAR                         158
+#define TK_FILL                           158
-#define TK_NEXT                           159
+#define TK_VALUE                          159
-#define TK_GROUP                          160
+#define TK_NONE                           160
-#define TK_HAVING                         161
+#define TK_PREV                           161
-#define TK_ORDER                          162
+#define TK_LINEAR                         162
-#define TK_SLIMIT                         163
+#define TK_NEXT                           163
-#define TK_SOFFSET                        164
+#define TK_GROUP                          164
-#define TK_LIMIT                          165
+#define TK_HAVING                         165
-#define TK_OFFSET                         166
+#define TK_ORDER                          166
-#define TK_ASC                            167
+#define TK_SLIMIT                         167
-#define TK_DESC                           168
+#define TK_SOFFSET                        168
-#define TK_NULLS                          169
+#define TK_LIMIT                          169
-#define TK_FIRST                          170
+#define TK_OFFSET                         170
-#define TK_LAST                           171
+#define TK_ASC                            171
+#define TK_DESC                           172
+#define TK_NULLS                          173
+#define TK_FIRST                          174
+#define TK_LAST                           175
 
 #define TK_NK_SPACE                       300
 #define TK_NK_COMMENT                     301

include/libs/nodes/nodes.h

@@ -70,6 +70,7 @@ typedef enum ENodeType {
   QUERY_NODE_DATABASE_OPTIONS,
   QUERY_NODE_TABLE_OPTIONS,
   QUERY_NODE_INDEX_OPTIONS,
+  QUERY_NODE_EXPLAIN_OPTIONS,
 
   // Statement nodes are used in parser and planner module.
   QUERY_NODE_SET_OPERATOR,
@@ -99,6 +100,7 @@ typedef enum ENodeType {
   QUERY_NODE_CREATE_TOPIC_STMT,
   QUERY_NODE_DROP_TOPIC_STMT,
   QUERY_NODE_ALTER_LOCAL_STMT,
+  QUERY_NODE_EXPLAIN_STMT,
   QUERY_NODE_SHOW_DATABASES_STMT,
   QUERY_NODE_SHOW_TABLES_STMT,
   QUERY_NODE_SHOW_STABLES_STMT,

include/libs/nodes/plannodes.h

@@ -49,6 +49,7 @@ typedef struct SScanLogicNode {
   STimeWindow scanRange;
   SName tableName;
   bool showRewrite;
+  double ratio;
 } SScanLogicNode;
 
 typedef struct SJoinLogicNode {
@@ -197,6 +198,7 @@ typedef struct STableScanPhysiNode {
   SScanPhysiNode scan;
   uint8_t scanFlag;         // denotes reversed scan of data or not
   STimeWindow scanRange;
+  double ratio;
 } STableScanPhysiNode;
 
 typedef STableScanPhysiNode STableSeqScanPhysiNode;
@@ -297,18 +299,23 @@ typedef struct SSubplan {
   SDataSinkNode* pDataSink;    // data of the subplan flow into the datasink
 } SSubplan;
 
-typedef enum EQueryMode {
+typedef enum EExplainMode {
-  QUERY_MODE_NORMAL = 1,
+  EXPLAIN_MODE_DISABLE = 1,
-  QUERY_MODE_EXPLAIN,
+  EXPLAIN_MODE_STATIC,
-  QUERY_MODE_EXPLAIN_AN
+  EXPLAIN_MODE_ANALYZE
-} EQueryMode;
+} EExplainMode;
+
+typedef struct SExplainInfo {
+  EExplainMode mode;
+  bool verbose;
+} SExplainInfo;
 
 typedef struct SQueryPlan {
   ENodeType type;
   uint64_t queryId;
   int32_t numOfSubplans;
-
   SNodeList* pSubplans; // Element is SNodeListNode. The execution level of subplan, starting from 0.
+  SExplainInfo explainInfo;
 } SQueryPlan;
 
 #ifdef __cplusplus

include/libs/nodes/querynodes.h

@@ -131,6 +131,7 @@ typedef struct SRealTableNode {
   struct STableMeta* pMeta;
   SVgroupsInfo* pVgroupList;
   char useDbName[TSDB_DB_NAME_LEN];
+  double ratio;
 } SRealTableNode;
 
 typedef struct STempTableNode {
@@ -282,6 +283,19 @@ typedef struct SVnodeModifOpStmt {
   const char* sql;                 // current sql statement position
 } SVnodeModifOpStmt;
 
+typedef struct SExplainOptions {
+  ENodeType type;
+  bool verbose;
+  double ratio;
+} SExplainOptions;
+
+typedef struct SExplainStmt {
+  ENodeType type;
+  bool analyze;
+  SExplainOptions* pOptions;
+  SNode* pQuery;
+} SExplainStmt;
+
 void nodesWalkSelectStmt(SSelectStmt* pSelect, ESqlClause clause, FNodeWalker walker, void* pContext);
 void nodesRewriteSelectStmt(SSelectStmt* pSelect, ESqlClause clause, FNodeRewriter rewriter, void* pContext);
 

include/util/tdef.h

@@ -381,6 +381,14 @@ typedef enum ELogicConditionType {
 #define TSDB_MAX_DB_DELAY     10
 #define TSDB_DEFAULT_DB_DELAY 2
 
+#define TSDB_DEFAULT_EXPLAIN_VERBOSE false
+
+#define TSDB_MIN_EXPLAIN_RATIO       0
+#define TSDB_MAX_EXPLAIN_RATIO       1
+#define TSDB_DEFAULT_EXPLAIN_RATIO   0.001
+
+#define TSDB_EXPLAIN_RESULT_ROW_SIZE 1024
+
 #define TSDB_MAX_JOIN_TABLE_NUM 10
 #define TSDB_MAX_UNION_CLAUSE   5
 

source/libs/nodes/src/nodesUtilFuncs.c

@@ -82,6 +82,8 @@ SNodeptr nodesMakeNode(ENodeType type) {
       return makeNode(type, sizeof(STableOptions));
     case QUERY_NODE_INDEX_OPTIONS:
       return makeNode(type, sizeof(SIndexOptions));
+    case QUERY_NODE_EXPLAIN_OPTIONS:
+      return makeNode(type, sizeof(SExplainOptions));
     case QUERY_NODE_SET_OPERATOR:
       return makeNode(type, sizeof(SSetOperator));
     case QUERY_NODE_SELECT_STMT:
@@ -132,6 +134,8 @@ SNodeptr nodesMakeNode(ENodeType type) {
       return makeNode(type, sizeof(SCreateTopicStmt));
     case QUERY_NODE_DROP_TOPIC_STMT:
       return makeNode(type, sizeof(SDropTopicStmt));
+    case QUERY_NODE_EXPLAIN_STMT:
+      return makeNode(type, sizeof(SExplainStmt));
     case QUERY_NODE_SHOW_DATABASES_STMT:
     case QUERY_NODE_SHOW_TABLES_STMT:
     case QUERY_NODE_SHOW_STABLES_STMT:

source/libs/parser/inc/parAst.h

@@ -159,6 +159,10 @@ SNode* createDropQnodeStmt(SAstCreateContext* pCxt, const SToken* pDnodeId);
 SNode* createCreateTopicStmt(SAstCreateContext* pCxt, bool ignoreExists, const SToken* pTopicName, SNode* pQuery, const SToken* pSubscribeDbName);
 SNode* createDropTopicStmt(SAstCreateContext* pCxt, bool ignoreNotExists, const SToken* pTopicName);
 SNode* createAlterLocalStmt(SAstCreateContext* pCxt, const SToken* pConfig, const SToken* pValue);
+SNode* createDefaultExplainOptions(SAstCreateContext* pCxt);
+SNode* setExplainVerbose(SAstCreateContext* pCxt, SNode* pOptions, const SToken* pVal);
+SNode* setExplainRatio(SAstCreateContext* pCxt, SNode* pOptions, const SToken* pVal);
+SNode* createExplainStmt(SAstCreateContext* pCxt, bool analyze, SNode* pOptions, SNode* pQuery);
 
 #ifdef __cplusplus
 }

source/libs/parser/inc/sql.y

@@ -339,6 +339,18 @@ cmd ::= CREATE TOPIC not_exists_opt(A) topic_name(B) AS query_expression(C).
 cmd ::= CREATE TOPIC not_exists_opt(A) topic_name(B) AS db_name(C).               { pCxt->pRootNode = createCreateTopicStmt(pCxt, A, &B, NULL, &C); }
 cmd ::= DROP TOPIC exists_opt(A) topic_name(B).                                   { pCxt->pRootNode = createDropTopicStmt(pCxt, A, &B); }
 
+/************************************************ select **************************************************************/
+cmd ::= EXPLAIN analyze_opt(A) explain_options(B) query_expression(C).            { pCxt->pRootNode = createExplainStmt(pCxt, A, B, C); }
+
+%type analyze_opt                                                                 { bool }
+%destructor analyze_opt                                                           { }
+analyze_opt(A) ::= .                                                              { A = false; }
+analyze_opt(A) ::= ANALYZE.                                                       { A = true; }
+
+explain_options(A) ::= .                                                          { A = createDefaultExplainOptions(pCxt); }
+explain_options(A) ::= explain_options(B) VERBOSE NK_BOOL(C).                     { A = setExplainVerbose(pCxt, B, &C); }
+explain_options(A) ::= explain_options(B) RATIO NK_FLOAT(C).                      { A = setExplainRatio(pCxt, B, &C); }
+
 /************************************************ select **************************************************************/
 cmd ::= query_expression(A).                                                      { pCxt->pRootNode = A; }
 

source/libs/parser/src/parAstCreater.c

@@ -1316,3 +1316,30 @@ SNode* createAlterLocalStmt(SAstCreateContext* pCxt, const SToken* pConfig, cons
   }
   return (SNode*)pStmt;
 }
+
+SNode* createDefaultExplainOptions(SAstCreateContext* pCxt) {
+  SExplainOptions* pOptions = nodesMakeNode(QUERY_NODE_EXPLAIN_OPTIONS);
+  CHECK_OUT_OF_MEM(pOptions);
+  pOptions->verbose = TSDB_DEFAULT_EXPLAIN_VERBOSE;
+  pOptions->ratio = TSDB_DEFAULT_EXPLAIN_RATIO;
+  return (SNode*)pOptions;
+}
+
+SNode* setExplainVerbose(SAstCreateContext* pCxt, SNode* pOptions, const SToken* pVal) {
+  ((SExplainOptions*)pOptions)->verbose = (0 == strncasecmp(pVal->z, "true", pVal->n));
+  return pOptions;
+}
+
+SNode* setExplainRatio(SAstCreateContext* pCxt, SNode* pOptions, const SToken* pVal) {
+  ((SExplainOptions*)pOptions)->ratio = strtod(pVal->z, NULL);
+  return pOptions;
+}
+
+SNode* createExplainStmt(SAstCreateContext* pCxt, bool analyze, SNode* pOptions, SNode* pQuery) {
+  SExplainStmt* pStmt = nodesMakeNode(QUERY_NODE_EXPLAIN_STMT);
+  CHECK_OUT_OF_MEM(pStmt);
+  pStmt->analyze = analyze;
+  pStmt->pOptions = (SExplainOptions*)pOptions;
+  pStmt->pQuery = pQuery;
+  return (SNode*)pStmt;
+}

source/libs/parser/src/parTokenizer.c

@@ -31,6 +31,7 @@ static SKeyword keywordTable[] = {
     {"ACCOUNT",       TK_ACCOUNT},
     {"ALL",           TK_ALL},
     {"ALTER",         TK_ALTER},
+    {"ANALYZE",       TK_ANALYZE},
     {"AND",           TK_AND},
     {"AS",            TK_AS},
     {"ASC",           TK_ASC},
@@ -56,6 +57,7 @@ static SKeyword keywordTable[] = {
     {"DOUBLE",        TK_DOUBLE},
     {"DROP",          TK_DROP},
     {"EXISTS",        TK_EXISTS},
+    {"EXPLAIN",       TK_EXPLAIN},
     {"FILE_FACTOR",   TK_FILE_FACTOR},
     {"FILL",          TK_FILL},
     {"FLOAT",         TK_FLOAT},
@@ -110,6 +112,7 @@ static SKeyword keywordTable[] = {
     {"QNODES",        TK_QNODES},
     {"QSTARTTS",      TK_QSTARTTS},
     {"QUORUM",        TK_QUORUM},
+    {"RATIO",         TK_RATIO},
     {"REPLICA",       TK_REPLICA},
     {"RETENTIONS",    TK_RETENTIONS},
     {"ROLLUP",        TK_ROLLUP},
@@ -144,6 +147,7 @@ static SKeyword keywordTable[] = {
     {"USING",         TK_USING},
     {"VALUES",        TK_VALUES},
     {"VARCHAR",       TK_VARCHAR},
+    {"VERBOSE",       TK_VERBOSE},
     {"VGROUPS",       TK_VGROUPS},
     {"WAL",           TK_WAL},
     {"WDURATION",     TK_WDURATION},
@@ -224,7 +228,6 @@ static SKeyword keywordTable[] = {
     // {"DETACH",       TK_DETACH},
     // {"EACH",         TK_EACH},
     // {"END",          TK_END},
-    // {"EXPLAIN",      TK_EXPLAIN},
     // {"FAIL",         TK_FAIL},
     // {"FOR",          TK_FOR},
     // {"IGNORE",       TK_IGNORE},

source/libs/parser/src/parTranslater.c

@@ -32,6 +32,7 @@ typedef struct STranslateContext {
   SCmdMsgInfo* pCmdMsg;
   SHashObj* pDbs;
   SHashObj* pTables;
+  SExplainOptions* pExplainOpt;
 } STranslateContext;
 
 typedef struct SFullDatabaseName {
@@ -673,6 +674,7 @@ static int32_t translateTable(STranslateContext* pCxt, SNode* pTable) {
   switch (nodeType(pTable)) {
     case QUERY_NODE_REAL_TABLE: {
       SRealTableNode* pRealTable = (SRealTableNode*)pTable;
+      pRealTable->ratio = (NULL != pCxt->pExplainOpt ? pCxt->pExplainOpt->ratio : 1.0);
       SName name;
       code = getTableMetaImpl(pCxt,
           toName(pCxt->pParseCxt->acctId, pRealTable->table.dbName, pRealTable->table.tableName, &name), &(pRealTable->pMeta));
@@ -680,10 +682,9 @@ static int32_t translateTable(STranslateContext* pCxt, SNode* pTable) {
         return generateSyntaxErrMsg(&pCxt->msgBuf, TSDB_CODE_PAR_TABLE_NOT_EXIST, pRealTable->table.tableName);
       }
       code = setTableVgroupList(pCxt, &name, pRealTable);
-      if (TSDB_CODE_SUCCESS != code) {
+      if (TSDB_CODE_SUCCESS == code) {
-        return code;
+        code = addNamespace(pCxt, pRealTable);
       }
-      code = addNamespace(pCxt, pRealTable);
       break;
     }
     case QUERY_NODE_TEMP_TABLE: {
@@ -1804,6 +1805,13 @@ static int32_t translateAlterLocal(STranslateContext* pCxt, SAlterLocalStmt* pSt
   return TSDB_CODE_SUCCESS;
 }
 
+static int32_t translateExplain(STranslateContext* pCxt, SExplainStmt* pStmt) {
+  if (pStmt->analyze) {
+    pCxt->pExplainOpt = pStmt->pOptions;
+  }
+  return translateQuery(pCxt, pStmt->pQuery);
+}
+
 static int32_t translateQuery(STranslateContext* pCxt, SNode* pNode) {
   int32_t code = TSDB_CODE_SUCCESS;
   switch (nodeType(pNode)) {
@@ -1885,6 +1893,9 @@ static int32_t translateQuery(STranslateContext* pCxt, SNode* pNode) {
     case QUERY_NODE_ALTER_LOCAL_STMT:
       code = translateAlterLocal(pCxt, (SAlterLocalStmt*)pNode);
       break;
+    case QUERY_NODE_EXPLAIN_STMT:
+      code = translateExplain(pCxt, (SExplainStmt*)pNode);
+      break;
     default:
       break;
   }
@@ -1903,7 +1914,11 @@ static int32_t translateSubquery(STranslateContext* pCxt, SNode* pNode) {
 }
 
 int32_t qExtractResultSchema(const SNode* pRoot, int32_t* numOfCols, SSchema** pSchema) {
-  if (NULL != pRoot && QUERY_NODE_SELECT_STMT == nodeType(pRoot)) {
+  if (NULL == pRoot) {
+    return TSDB_CODE_SUCCESS;
+  }
+
+  if (QUERY_NODE_SELECT_STMT == nodeType(pRoot)) {
     SSelectStmt* pSelect = (SSelectStmt*) pRoot;
     *numOfCols = LIST_LENGTH(pSelect->pProjectionList);
     *pSchema = taosMemoryCalloc((*numOfCols), sizeof(SSchema));
@@ -1921,6 +1936,14 @@ int32_t qExtractResultSchema(const SNode* pRoot, int32_t* numOfCols, SSchema** p
       strcpy((*pSchema)[index].name, pExpr->aliasName);
       index +=1;
     }
+  } else if (QUERY_NODE_EXPLAIN_STMT == nodeType(pRoot)) {
+    *numOfCols = 1;
+    *pSchema = taosMemoryCalloc((*numOfCols), sizeof(SSchema));
+    if (NULL == (*pSchema)) {
+      return TSDB_CODE_OUT_OF_MEMORY;
+    }
+    (*pSchema)[0].type = TSDB_DATA_TYPE_BINARY;
+    (*pSchema)[0].bytes = TSDB_EXPLAIN_RESULT_ROW_SIZE;
   }
 
   return TSDB_CODE_SUCCESS;
@@ -2505,6 +2528,7 @@ static int32_t rewriteQuery(STranslateContext* pCxt, SQuery* pQuery) {
 static int32_t setQuery(STranslateContext* pCxt, SQuery* pQuery) {
   switch (nodeType(pQuery->pRoot)) {
     case QUERY_NODE_SELECT_STMT:
+    case QUERY_NODE_EXPLAIN_STMT:
       pQuery->haveResultSet = true;
       pQuery->directRpc = false;
       pQuery->msgType = TDMT_VND_QUERY;

source/libs/parser/test/parserAstTest.cpp

@@ -647,3 +647,16 @@ TEST_F(ParserTest, dropTopic) {
   bind("drop topic if exists tp1");
   ASSERT_TRUE(run());
 }
+
+TEST_F(ParserTest, explain) {
+  setDatabase("root", "test");
+
+  bind("explain SELECT * FROM t1");
+  ASSERT_TRUE(run());
+
+  bind("explain analyze SELECT * FROM t1");
+  ASSERT_TRUE(run());
+
+  bind("explain analyze verbose true ratio 0.01 SELECT * FROM t1");
+  ASSERT_TRUE(run());
+}

source/libs/planner/src/planLogicCreater.c

@@ -197,6 +197,7 @@ static int32_t createScanLogicNode(SLogicPlanContext* pCxt, SSelectStmt* pSelect
   strcpy(pScan->tableName.dbname, pRealTable->table.dbName);
   strcpy(pScan->tableName.tname, pRealTable->table.tableName);
   pScan->showRewrite = pCxt->pPlanCxt->showRewrite;
+  pScan->ratio = pRealTable->ratio;
 
   // set columns to scan
   SNodeList* pCols = NULL;
@@ -704,6 +705,8 @@ static int32_t createQueryLogicNode(SLogicPlanContext* pCxt, SNode* pStmt, SLogi
       return createSelectLogicNode(pCxt, (SSelectStmt*)pStmt, pLogicNode);
     case QUERY_NODE_VNODE_MODIF_STMT:
       return createVnodeModifLogicNode(pCxt, (SVnodeModifOpStmt*)pStmt, pLogicNode);
+    case QUERY_NODE_EXPLAIN_STMT:
+      return createQueryLogicNode(pCxt, ((SExplainStmt*)pStmt)->pQuery, pLogicNode);
     default:
       break;
   }

source/libs/planner/src/planPhysiCreater.c

@@ -398,6 +398,7 @@ static int32_t createTableScanPhysiNode(SPhysiPlanContext* pCxt, SSubplan* pSubp
 
   pTableScan->scanFlag = pScanLogicNode->scanFlag;
   pTableScan->scanRange = pScanLogicNode->scanRange;
+  pTableScan->ratio = pScanLogicNode->ratio;
   vgroupInfoToNodeAddr(pScanLogicNode->pVgroupList->vgroups, &pSubplan->execNode);
   taosArrayPush(pCxt->pExecNodeList, &pSubplan->execNode);
   pSubplan->execNodeStat.tableNum = pScanLogicNode->pVgroupList->vgroups[0].numOfTable;
@@ -1095,6 +1096,16 @@ static void destoryPhysiPlanContext(SPhysiPlanContext* pCxt) {
   taosArrayDestroyEx(pCxt->pLocationHelper, destoryLocationHash);
 }
 
+static void setExplainInfo(SPlanContext* pCxt, SQueryPlan* pPlan) {
+  if (QUERY_NODE_EXPLAIN_STMT == nodeType(pCxt->pAstRoot)) {
+    SExplainStmt* pStmt = (SExplainStmt*)pCxt->pAstRoot;
+    pPlan->explainInfo.mode = pStmt->analyze ? EXPLAIN_MODE_ANALYZE : EXPLAIN_MODE_STATIC;
+    pPlan->explainInfo.verbose = pStmt->pOptions->verbose;
+  } else {
+    pPlan->explainInfo.mode = EXPLAIN_MODE_DISABLE;
+  }
+}
+
 int32_t createPhysiPlan(SPlanContext* pCxt, SQueryLogicPlan* pLogicPlan, SQueryPlan** pPlan, SArray* pExecNodeList) {
   SPhysiPlanContext cxt = {
     .pPlanCxt = pCxt,
@@ -1106,7 +1117,12 @@ int32_t createPhysiPlan(SPlanContext* pCxt, SQueryLogicPlan* pLogicPlan, SQueryP
   if (NULL == cxt.pLocationHelper) {
     return TSDB_CODE_OUT_OF_MEMORY;
   }
+
   int32_t code = doCreatePhysiPlan(&cxt, pLogicPlan, pPlan);
+  if (TSDB_CODE_SUCCESS == code) {
+    setExplainInfo(pCxt, *pPlan);
+  }
+
   destoryPhysiPlanContext(&cxt);
   return code;
 }

source/libs/planner/test/plannerTest.cpp

@@ -282,3 +282,16 @@ TEST_F(PlannerTest, createSmaIndex) {
   bind("create sma index index1 on t1 function(max(c1), min(c3 + 10), sum(c4)) INTERVAL(10s)");
   ASSERT_TRUE(run());
 }
+
+TEST_F(PlannerTest, explain) {
+  setDatabase("root", "test");
+
+  bind("explain SELECT * FROM t1");
+  ASSERT_TRUE(run());
+
+  bind("explain analyze SELECT * FROM t1");
+  ASSERT_TRUE(run());
+
+  bind("explain analyze verbose true ratio 0.01 SELECT * FROM t1");
+  ASSERT_TRUE(run());
+}