planner: improve the error message for hints defined more than once (#…

…16301)
pingcap · Jun 1, 2020 · 8a164d2 · 8a164d2
1 parent 7b2d79c
commit 8a164d2
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Showing 2 changed files with 6 additions and 6 deletions.
diff --git a/planner/optimize.go b/planner/optimize.go
@@ -332,7 +332,7 @@ func handleStmtHints(hints []*ast.TableOptimizerHint) (stmtHints stmtctx.StmtHin
 	// Handle MEMORY_QUOTA
 	if memoryQuotaHintCnt != 0 {
 		if memoryQuotaHintCnt > 1 {
-			warn := errors.New("There are multiple MEMORY_QUOTA hints, only the last one will take effect")
+			warn := errors.Errorf("MEMORY_QUOTA() s defined more than once, only the last definition takes effect: MEMORY_QUOTA(%v)", memoryQuotaHint.HintData.(int64))
 			warns = append(warns, warn)
 		}
 		// Executor use MemoryQuota <= 0 to indicate no memory limit, here use < 0 to handle hint syntax error.
@@ -351,7 +351,7 @@ func handleStmtHints(hints []*ast.TableOptimizerHint) (stmtHints stmtctx.StmtHin
 	// Handle USE_TOJA
 	if useToJAHintCnt != 0 {
 		if useToJAHintCnt > 1 {
-			warn := errors.New("There are multiple USE_TOJA hints, only the last one will take effect")
+			warn := errors.Errorf("USE_TOJA() is defined more than once, only the last definition takes effect: USE_TOJA(%v)", useToJAHint.HintData.(bool))
 			warns = append(warns, warn)
 		}
 		stmtHints.HasAllowInSubqToJoinAndAggHint = true
@@ -369,15 +369,15 @@ func handleStmtHints(hints []*ast.TableOptimizerHint) (stmtHints stmtctx.StmtHin
 	// Handle NO_INDEX_MERGE
 	if noIndexMergeHintCnt != 0 {
 		if noIndexMergeHintCnt > 1 {
-			warn := errors.New("There are multiple NO_INDEX_MERGE hints, only the last one will take effect")
+			warn := errors.New("NO_INDEX_MERGE() is defined more than once, only the last definition takes effect")
 			warns = append(warns, warn)
 		}
 		stmtHints.NoIndexMergeHint = true
 	}
 	// Handle READ_CONSISTENT_REPLICA
 	if readReplicaHintCnt != 0 {
 		if readReplicaHintCnt > 1 {
-			warn := errors.New("There are multiple READ_CONSISTENT_REPLICA hints, only the last one will take effect")
+			warn := errors.New("READ_CONSISTENT_REPLICA() is defined more than once, only the last definition takes effect")
 			warns = append(warns, warn)
 		}
 		stmtHints.HasReplicaReadHint = true
@@ -386,7 +386,7 @@ func handleStmtHints(hints []*ast.TableOptimizerHint) (stmtHints stmtctx.StmtHin
 	// Handle MAX_EXECUTION_TIME
 	if maxExecutionTimeCnt != 0 {
 		if maxExecutionTimeCnt > 1 {
-			warn := errors.New("There are multiple MAX_EXECUTION_TIME hints, only the last one will take effect")
+			warn := errors.Errorf("MAX_EXECUTION_TIME() is defined more than once, only the last definition takes effect: MAX_EXECUTION_TIME(%v)", maxExecutionTime.HintData.(uint64))
 			warns = append(warns, warn)
 		}
 		stmtHints.HasMaxExecutionTime = true

diff --git a/session/session_test.go b/session/session_test.go
@@ -2966,7 +2966,7 @@ func (s *testSessionSuite3) TestMaxExeucteTime(c *C) {
 
 	tk.MustQuery("select /*+ MAX_EXECUTION_TIME(1000) MAX_EXECUTION_TIME(500) */ * FROM MaxExecTime;")
 	c.Assert(tk.Se.GetSessionVars().StmtCtx.GetWarnings(), HasLen, 1)
-	c.Assert(tk.Se.GetSessionVars().StmtCtx.GetWarnings()[0].Err.Error(), Equals, "There are multiple MAX_EXECUTION_TIME hints, only the last one will take effect")
+	c.Assert(tk.Se.GetSessionVars().StmtCtx.GetWarnings()[0].Err.Error(), Equals, "MAX_EXECUTION_TIME() is defined more than once, only the last definition takes effect: MAX_EXECUTION_TIME(500)")
 	c.Assert(tk.Se.GetSessionVars().StmtCtx.HasMaxExecutionTime, Equals, true)
 	c.Assert(tk.Se.GetSessionVars().StmtCtx.MaxExecutionTime, Equals, uint64(500))