fix statistic sql for plan data

Author: chris-sun-star

internal/sql-analyzer/const/sql/sql_plan.go

@@ -97,20 +97,42 @@ const (
 			FROM sql_plan
 			WHERE SQL_ID = ?
 			GROUP BY TENANT_ID, SVR_IP, SVR_PORT, PLAN_ID, PLAN_HASH
+		),
+		PlanStats AS (
+			SELECT
+				PLAN_HASH,
+				CAST(AVG(IO_COST) AS BIGINT) as IO_COST,
+				CAST(AVG(CPU_COST) AS BIGINT) as CPU_COST,
+				CAST(AVG(COST) AS BIGINT) as COST,
+				CAST(AVG(REAL_COST) AS BIGINT) as REAL_COST
+			FROM PlanAgg
+			GROUP BY PLAN_HASH
+		),
+		LatestPlan AS (
+			SELECT
+				TENANT_ID,
+				SVR_IP,
+				SVR_PORT,
+				PLAN_ID,
+				PLAN_HASH,
+				GMT_CREATE,
+				ROW_NUMBER() OVER (PARTITION BY PLAN_HASH ORDER BY GMT_CREATE DESC, PLAN_ID DESC) as rn
+			FROM PlanAgg
 		)
 		SELECT
-			MAX(TENANT_ID) as TENANT_ID,
-			MAX(SVR_IP) as SVR_IP,
-			MAX(SVR_PORT) as SVR_PORT,
-			MAX(PLAN_ID) as PLAN_ID,
-			PLAN_HASH,
-			MAX(GMT_CREATE) as GMT_CREATE,
-			CAST(AVG(IO_COST) AS BIGINT) as IO_COST,
-			CAST(AVG(CPU_COST) AS BIGINT) as CPU_COST,
-			CAST(AVG(COST) AS BIGINT) as COST,
-			CAST(AVG(REAL_COST) AS BIGINT) as REAL_COST
-		FROM PlanAgg
-		GROUP BY PLAN_HASH
+			lp.TENANT_ID,
+			lp.SVR_IP,
+			lp.SVR_PORT,
+			lp.PLAN_ID,
+			lp.PLAN_HASH,
+			lp.GMT_CREATE,
+			ps.IO_COST,
+			ps.CPU_COST,
+			ps.COST,
+			ps.REAL_COST
+		FROM LatestPlan lp
+		JOIN PlanStats ps ON lp.PLAN_HASH = ps.PLAN_HASH
+		WHERE lp.rn = 1
 	`
 	GetTableInfo = `
 		SELECT