planner: output a SQL warning if binding loading is triggered

pkg/bindinfo/binding_cache.go

@@ -153,6 +153,10 @@ func (fbc *fuzzyBindingCache) loadFromStore(sctx sessionctx.Context, missingSQLD
 	if intest.InTest && sctx.Value(LoadBindingNothing) != nil {
 		return
 	}
+	defer func(start time.Time) {
+		sctx.GetSessionVars().StmtCtx.AppendWarning(errors.New("loading binding from storage takes " + time.Since(start).String()))
+	}(time.Now())
+
 	for _, sqlDigest := range missingSQLDigest {
 		start := time.Now()
 		bindings, err := fbc.loadBindingFromStorageFunc(sctx, sqlDigest)
@@ -173,7 +177,7 @@ func (fbc *fuzzyBindingCache) loadFromStore(sctx sessionctx.Context, missingSQLD
 				// When the memory capacity of bing_cache is not enough,
 				// there will be some memory-related errors in multiple places.
 				// Only needs to be handled once.
-				logutil.BindLogger().Warn("BindHandle.Update", zap.Error(err))
+				logutil.BindLogger().Warn("update binding cache error", zap.Error(err))
 			}
 		}
 	}

pkg/bindinfo/tests/timeout/BUILD.bazel

@@ -12,6 +12,7 @@ go_test(
         "//pkg/bindinfo",
         "//pkg/testkit",
         "//pkg/testkit/testsetup",
+        "@com_github_stretchr_testify//require",
         "@org_uber_go_goleak//:goleak",
     ],
 )

pkg/bindinfo/tests/timeout/timeout_test.go

@@ -20,8 +20,26 @@ import (
 
 	"github.com/pingcap/tidb/pkg/bindinfo"
 	"github.com/pingcap/tidb/pkg/testkit"
+	"github.com/stretchr/testify/require"
 )
 
+func TestLoadBindingWarn(t *testing.T) {
+	store := testkit.CreateMockStore(t)
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec(`use test`)
+	tk.MustExec(`create table t1 (a int)`)
+	tk.MustExec(`create global binding using select * from t1`)
+	tk.MustExec(`select * from t1`)
+	tk.MustQuery(`show warnings`).Check(testkit.Rows()) // no warning
+
+	sctx := tk.Session()
+	sctx.SetValue(bindinfo.GetBindingReturnNilAlways, true)
+	tk.MustExec(`select * from t1`)
+	warnings := tk.MustQuery(`show warnings`)
+	require.True(t, len(warnings.Rows()) == 1)
+	sctx.ClearValue(bindinfo.GetBindingReturnNilAlways)
+}
+
 func TestFuzzyBindingHintsWithSourceReturningTimeout(t *testing.T) {
 	store := testkit.CreateMockStore(t)
 	tk := testkit.NewTestKit(t, store)

tests/integrationtest/r/planner/core/integration.result

@@ -305,54 +305,6 @@ c2	c0
 0	0
 1	1
 0	1
-drop table if exists t;
-create table t(a int, b int, unique index i_a (a) invisible, unique index i_b(b));
-insert into t values (1,2);
-admin check table t;
-select a from t order by a;
-a
-1
-explain select a from t order by a;
-id	estRows	task	access object	operator info
-Sort_4	10000.00	root		planner__core__integration.t.a
-└─TableReader_8	10000.00	root		data:TableFullScan_7
-  └─TableFullScan_7	10000.00	cop[tikv]	table:t	keep order:false, stats:pseudo
-select a from t where a > 0;
-a
-1
-explain select a from t where a > 1;
-id	estRows	task	access object	operator info
-TableReader_7	3333.33	root		data:Selection_6
-└─Selection_6	3333.33	cop[tikv]		gt(planner__core__integration.t.a, 1)
-  └─TableFullScan_5	10000.00	cop[tikv]	table:t	keep order:false, stats:pseudo
-select * from t use index(i_a);
-Error 1176 (42000): Key 'i_a' doesn't exist in table 't'
-select * from t force index(i_a);
-Error 1176 (42000): Key 'i_a' doesn't exist in table 't'
-select * from t ignore index(i_a);
-Error 1176 (42000): Key 'i_a' doesn't exist in table 't'
-select /*+ USE_INDEX(t, i_a) */ * from t;
-a	b
-1	2
-Level	Code	Message
-Warning	1176	Key 'i_a' doesn't exist in table 't'
-select /*+ IGNORE_INDEX(t, i_a), USE_INDEX(t, i_b) */ a from t order by a;
-a
-1
-Level	Code	Message
-Warning	1176	Key 'i_a' doesn't exist in table 't'
-select /*+ FORCE_INDEX(t, i_a), USE_INDEX(t, i_b) */ a from t order by a;
-a
-1
-Level	Code	Message
-Warning	1176	Key 'i_a' doesn't exist in table 't'
-select /*+ FORCE_INDEX(aaa) */ * from t;
-a	b
-1	2
-Level	Code	Message
-Warning	1815	force_index(planner__core__integration.aaa) is inapplicable, check whether the table(planner__core__integration.aaa) exists
-admin check table t;
-admin check index t i_a;
 select max(t.col) from (select 'a' as col union all select '' as col) as t;
 max(t.col)
 a

tests/integrationtest/t/planner/core/integration.test

@@ -234,31 +234,6 @@ INSERT INTO t0(c0) VALUES (3);
 SELECT /*+ MERGE_JOIN(t1, t0, v0)*/v0.c2, t1.c0 FROM v0,  t0 CROSS JOIN t1 ORDER BY -v0.c1;
 
 
-# TestInvisibleIndex
-drop table if exists t;
-create table t(a int, b int, unique index i_a (a) invisible, unique index i_b(b));
-insert into t values (1,2);
-admin check table t;
-select a from t order by a;
-explain select a from t order by a;
-select a from t where a > 0;
-explain select a from t where a > 1;
---error 1176
-select * from t use index(i_a);
---error 1176
-select * from t force index(i_a);
---error 1176
-select * from t ignore index(i_a);
---enable_warnings
-select /*+ USE_INDEX(t, i_a) */ * from t;
-select /*+ IGNORE_INDEX(t, i_a), USE_INDEX(t, i_b) */ a from t order by a;
-select /*+ FORCE_INDEX(t, i_a), USE_INDEX(t, i_b) */ a from t order by a;
-select /*+ FORCE_INDEX(aaa) */ * from t;
---disable_warnings
-admin check table t;
-admin check index t i_a;
-
-
 # TestTopNByConstFunc
 select max(t.col) from (select 'a' as col union all select '' as col) as t;