planner: forbid the optimizer to generate point-plan upon MVIndexes (#…

…40804) ref #40191
pingcap · Jan 29, 2023 · 774d2eb · 774d2eb
1 parent 4686338
commit 774d2eb
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Showing 3 changed files with 29 additions and 2 deletions.
diff --git a/planner/core/find_best_task.go b/planner/core/find_best_task.go
@@ -944,6 +944,9 @@ func (ds *DataSource) findBestTask(prop *property.PhysicalProperty, planCounter
 		if canConvertPointGet && expression.MaybeOverOptimized4PlanCache(ds.ctx, path.AccessConds) {
 			canConvertPointGet = ds.canConvertToPointGetForPlanCache(path)
 		}
+		if canConvertPointGet && path.Index != nil && path.Index.MVIndex {
+			canConvertPointGet = false // cannot use PointGet upon MVIndex
+		}
 
 		if canConvertPointGet && !path.IsIntHandlePath {
 			// We simply do not build [batch] point get for prefix indexes. This can be optimized.

diff --git a/planner/core/indexmerge_path_test.go b/planner/core/indexmerge_path_test.go
@@ -15,11 +15,13 @@
 package core_test
 
 import (
+	"strings"
 	"testing"
 
 	"github.com/pingcap/tidb/planner/core"
 	"github.com/pingcap/tidb/testkit"
 	"github.com/pingcap/tidb/testkit/testdata"
+	"github.com/stretchr/testify/require"
 )
 
 func TestIndexMergeJSONMemberOf(t *testing.T) {
@@ -149,3 +151,25 @@ func TestMVIndexIndexMergePlanCache(t *testing.T) {
 	tk.MustExec("execute st")
 	tk.MustQuery("select @@last_plan_from_cache").Check(testkit.Rows("0"))
 }
+
+func TestMVIndexPointGet(t *testing.T) {
+	store := testkit.CreateMockStore(t)
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec("use test")
+	tk.MustExec(`create table t(j json, unique kj((cast(j as signed array))))`)
+
+	for _, sql := range []string{
+		"select j from t where j=1",
+		"select j from t where j=1 or j=2",
+		"select j from t where j in (1, 2)",
+	} {
+		plan := tk.MustQuery("explain " + sql).Rows()
+		hasPointGet := false
+		for _, line := range plan {
+			if strings.Contains(strings.ToLower(line[0].(string)), "point") {
+				hasPointGet = true
+			}
+		}
+		require.True(t, !hasPointGet) // no point-get plan
+	}
+}
diff --git a/planner/core/point_get_plan.go b/planner/core/point_get_plan.go
@@ -731,7 +731,7 @@ func newBatchPointGetPlan(
 		}
 	}
 	for _, idxInfo := range tbl.Indices {
-		if !idxInfo.Unique || idxInfo.State != model.StatePublic || idxInfo.Invisible ||
+		if !idxInfo.Unique || idxInfo.State != model.StatePublic || idxInfo.Invisible || idxInfo.MVIndex ||
 			!indexIsAvailableByHints(idxInfo, indexHints) {
 			continue
 		}
@@ -1099,7 +1099,7 @@ func tryPointGetPlan(ctx sessionctx.Context, selStmt *ast.SelectStmt, check bool
 	var err error
 
 	for _, idxInfo := range tbl.Indices {
-		if !idxInfo.Unique || idxInfo.State != model.StatePublic || idxInfo.Invisible ||
+		if !idxInfo.Unique || idxInfo.State != model.StatePublic || idxInfo.Invisible || idxInfo.MVIndex ||
 			!indexIsAvailableByHints(idxInfo, tblName.IndexHints) {
 			continue
 		}