*: insert/update or explain should not trigger table cache condition (#…

…29477)
pingcap · Nov 8, 2021 · a78e7fe · a78e7fe
1 parent 74eaa06
commit a78e7fe
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Showing 3 changed files with 79 additions and 16 deletions.
diff --git a/planner/core/logical_plan_builder.go b/planner/core/logical_plan_builder.go
@@ -4160,9 +4160,15 @@ func (b *PlanBuilder) buildDataSource(ctx context.Context, tn *ast.TableName, as
 			result = us
 		} else {
 			go func() {
-				err := cachedTable.UpdateLockForRead(b.ctx, txn.StartTS())
-				if err != nil {
-					log.Warn("Update Lock Info Error")
+				defer func() {
+					if r := recover(); r != nil {
+					}
+				}()
+				if !b.inUpdateStmt && !b.inDeleteStmt && !b.ctx.GetSessionVars().StmtCtx.InExplainStmt {
+					err := cachedTable.UpdateLockForRead(b.ctx, txn.StartTS())
+					if err != nil {
+						log.Warn("Update Lock Info Error")
+					}
 				}
 			}()
 		}

diff --git a/sessionctx/stmtctx/stmtctx.go b/sessionctx/stmtctx/stmtctx.go
@@ -355,6 +355,11 @@ func (sc *StatementContext) GetCacheTable(tblID int64) (bool, interface{}) {
 	return false, nil
 }
 
+// CacheTableUsed is used by test to check whether the last query use table cache.
+func (sc *StatementContext) CacheTableUsed() bool {
+	return len(sc.cachedTables) > 0
+}
+
 // TableEntry presents table in db.
 type TableEntry struct {
 	DB    string

diff --git a/table/tables/cache_test.go b/table/tables/cache_test.go
@@ -18,10 +18,10 @@ import (
 	"testing"
 
 	"github.com/pingcap/tidb/testkit"
+	"github.com/stretchr/testify/require"
 )
 
 func TestCacheTableBasicScan(t *testing.T) {
-	t.Parallel()
 	store, clean := testkit.CreateMockStore(t)
 	defer clean()
 	tk := testkit.NewTestKit(t, store)
@@ -45,13 +45,19 @@ func TestCacheTableBasicScan(t *testing.T) {
 		tk.MustExec("create table join_t1  (id int)")
 		tk.MustExec("insert into join_t1 values(1)")
 		tk.MustExec("alter table join_t1 cache")
-		tk.MustExec("select *from join_t1")
+		tk.MustQuery("select *from join_t1").Check(testkit.Rows("1"))
 		tk.MustExec("create table join_t2  (id int)")
 		tk.MustExec("insert into join_t2 values(2)")
 		tk.MustExec("alter table join_t2 cache")
-		tk.MustExec("select *from join_t2")
+		tk.MustQuery("select *from join_t2").Check(testkit.Rows("2"))
 		tk.MustExec("create table join_t3 (id int)")
 		tk.MustExec("insert into join_t3 values(3)")
+		for i := 0; i < 10; i++ {
+			tk.MustQuery("select *from join_t1 join join_t2").Check(testkit.Rows("1 2"))
+			if tk.Session().GetSessionVars().StmtCtx.CacheTableUsed() {
+				break
+			}
+		}
 		result := tk.MustQuery("explain format = 'brief' select *from join_t1 join join_t2")
 		result.Check(testkit.Rows(
 			"HashJoin 100000000.00 root  CARTESIAN inner join",
@@ -61,8 +67,13 @@ func TestCacheTableBasicScan(t *testing.T) {
 			"└─UnionScan(Probe) 10000.00 root  ",
 			"  └─TableReader 10000.00 root  data:TableFullScan",
 			"    └─TableFullScan 10000.00 cop[tikv] table:join_t1 keep order:false, stats:pseudo"))
-		tk.MustQuery("select *from join_t1 join join_t2").Check(testkit.Rows("1 2"))
 		// Test for join a cache table and a normal table
+		for i := 0; i < 10; i++ {
+			tk.MustQuery("select *from join_t1 join join_t3").Check(testkit.Rows("1 3"))
+			if tk.Session().GetSessionVars().StmtCtx.CacheTableUsed() {
+				break
+			}
+		}
 		result = tk.MustQuery("explain format = 'brief' select *from join_t1 join join_t3")
 		result.Check(testkit.Rows(
 			"Projection 100000000.00 root  test.join_t1.id, test.join_t3.id",
@@ -73,26 +84,35 @@ func TestCacheTableBasicScan(t *testing.T) {
 			"  └─TableReader(Probe) 10000.00 root  data:TableFullScan",
 			"    └─TableFullScan 10000.00 cop[tikv] table:join_t3 keep order:false, stats:pseudo"))
 
-		tk.MustQuery("select *from join_t1 join join_t3").Check(testkit.Rows("1 3"))
 		// Second read will from cache table
+		for i := 0; i < 10; i++ {
+			tk.MustQuery("select * from tmp1 where id>4 order by id").Check(testkit.Rows(
+				"5 105 1005", "7 117 1007", "9 109 1009",
+				"10 110 1010", "12 112 1012", "14 114 1014", "16 116 1016", "18 118 1018",
+			))
+			if tk.Session().GetSessionVars().StmtCtx.CacheTableUsed() {
+				break
+			}
+		}
 		result = tk.MustQuery("explain format = 'brief' select * from tmp1 where id>4 order by id")
 		result.Check(testkit.Rows("UnionScan 3333.33 root  gt(test.tmp1.id, 4)",
 			"└─TableReader 3333.33 root  data:TableRangeScan",
 			"  └─TableRangeScan 3333.33 cop[tikv] table:tmp1 range:(4,+inf], keep order:true, stats:pseudo"))
-		tk.MustQuery("select * from tmp1 where id>4 order by id").Check(testkit.Rows(
-			"5 105 1005", "7 117 1007", "9 109 1009",
-			"10 110 1010", "12 112 1012", "14 114 1014", "16 116 1016", "18 118 1018",
-		))
 		// For IndexLookUpReader
+		for i := 0; i < 10; i++ {
+			tk.MustQuery("select /*+ use_index(tmp1, u) */ * from tmp1 where u>101 order by u").Check(testkit.Rows(
+				"5 105 1005", "9 109 1009", "10 110 1010",
+				"12 112 1012", "3 113 1003", "14 114 1014", "16 116 1016", "7 117 1007", "18 118 1018",
+			))
+			if tk.Session().GetSessionVars().StmtCtx.CacheTableUsed() {
+				break
+			}
+		}
 		result = tk.MustQuery("explain format = 'brief' select /*+ use_index(tmp1, u) */ * from tmp1 where u>101 order by u")
 		result.Check(testkit.Rows("UnionScan 3333.33 root  gt(test.tmp1.u, 101)",
 			"└─IndexLookUp 3333.33 root  ",
 			"  ├─IndexRangeScan(Build) 3333.33 cop[tikv] table:tmp1, index:u(u) range:(101,+inf], keep order:true, stats:pseudo",
 			"  └─TableRowIDScan(Probe) 3333.33 cop[tikv] table:tmp1 keep order:false, stats:pseudo"))
-		tk.MustQuery("select /*+ use_index(tmp1, u) */ * from tmp1 where u>101 order by u").Check(testkit.Rows(
-			"5 105 1005", "9 109 1009", "10 110 1010",
-			"12 112 1012", "3 113 1003", "14 114 1014", "16 116 1016", "7 117 1007", "18 118 1018",
-		))
 		tk.MustQuery("show warnings").Check(testkit.Rows())
 
 		// For IndexReader
@@ -113,3 +133,35 @@ func TestCacheTableBasicScan(t *testing.T) {
 	assertSelect()
 
 }
+
+func TestCacheCondition(t *testing.T) {
+	store, clean := testkit.CreateMockStore(t)
+	defer clean()
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec("use test")
+	tk.MustExec("drop table if exists t2")
+	tk.MustExec("create table t2 (id int primary key, v int)")
+	tk.MustExec("alter table t2 cache")
+
+	// Explain should not trigger cache.
+	tk.MustQuery("explain select * from t2")
+	require.False(t, tk.HasPlan("select * from t2 where id>0", "UnionScan"))
+
+	// Insert should not trigger cache.
+	tk.MustExec("insert into t2 values (1,1)")
+	require.False(t, tk.HasPlan("select * from t2 where id>0", "UnionScan"))
+
+	// Update should not trigger cache.
+	tk.MustExec("update t2 set v = v + 1 where id > 0")
+	require.False(t, tk.HasPlan("select * from t2 where id>0", "UnionScan"))
+
+	// Normal query should trigger cache.
+	tk.MustQuery("select * from t2")
+	var i int
+	for ; i < 10; i++ {
+		if tk.HasPlan("select * from t2 where id>0", "UnionScan") {
+			return
+		}
+	}
+	require.True(t, i < 10)
+}