update

Signed-off-by: Weizhen Wang <wangweizhen@pingcap.com>

Author: hawkingrei

pkg/planner/core/casetest/enforcempp/enforce_mpp_test.go

@@ -646,11 +646,13 @@ func TestReadCommittedWithTiflash(t *testing.T) {
 	tk.MustExec("set @@session.tidb_isolation_read_engines=\"tidb,tiflash\"")
 	tk.MustExec("begin;")
 	tk.MustQuery(`explain format='plan_tree' select /*+ set_var(tidb_enforce_mpp=on) */ * from t1 join t2 on t1.a=t2.b where t1.a in (1,2);`).Check(testkit.Rows(
-		`HashJoin root  inner join, equal:[eq(test.t1.a, test.t2.b)]`,
-		`├─Batch_Point_Get(Build) root table:t1 handle:[1 2], keep order:false, desc:false`,
-		`└─TableReader(Probe) root  MppVersion: 3, data:ExchangeSender`,
-		`  └─ExchangeSender mpp[tiflash]  ExchangeType: PassThrough`,
-		`    └─TableFullScan mpp[tiflash] table:t2 pushed down filter:in(test.t2.b, 1, 2), not(isnull(test.t2.b)), keep order:false, stats:pseudo`))
+		`TableReader root  MppVersion: 3, data:ExchangeSender`,
+		`└─ExchangeSender mpp[tiflash]  ExchangeType: PassThrough`,
+		`  └─HashJoin mpp[tiflash]  inner join, equal:[eq(test.t1.a, test.t2.b)]`,
+		`    ├─ExchangeReceiver(Build) mpp[tiflash]  `,
+		`    │ └─ExchangeSender mpp[tiflash]  ExchangeType: Broadcast, Compression: FAST`,
+		`    │   └─TableRangeScan mpp[tiflash] table:t1 range:[1,1], [2,2], keep order:false, stats:pseudo`,
+		`    └─TableFullScan(Probe) mpp[tiflash] table:t2 pushed down filter:in(test.t2.b, 1, 2), not(isnull(test.t2.b)), keep order:false, stats:pseudo`))
 	tk.MustQuery(`explain format='plan_tree' select * from t1 join t2 on t1.a=t2.b where t1.a in (1,2);`).Check(testkit.Rows(
 		`HashJoin root  inner join, equal:[eq(test.t1.a, test.t2.b)]`,
 		`├─Batch_Point_Get(Build) root table:t1 handle:[1 2], keep order:false, desc:false`,

pkg/planner/core/find_best_task.go

@@ -1643,7 +1643,7 @@ func findBestTask4LogicalDataSource(super base.LogicalPlan, prop *property.Physi
 	}
 	sessionVars := ds.SCtx().GetSessionVars()
 	_, isolationReadEnginesHasTiKV := sessionVars.GetIsolationReadEngines()[kv.TiKV]
-	if ds.IsForUpdateRead && sessionVars.TxnCtx.IsExplicit && isolationReadEnginesHasTiKV {
+	if ds.IsForUpdateRead && sessionVars.TxnCtx.IsExplicit && isolationReadEnginesHasTiKV && !sessionVars.IsMPPEnforced() {
 		hasPointGetPath := false
 		for _, path := range ds.PossibleAccessPaths {
 			if isPointGetPath(ds, path) {

pkg/planner/core/logical_plan_builder.go

@@ -522,7 +522,7 @@ func setPreferredStoreType(ds *logicalop.DataSource, hintInfo *h.PlanHints) {
 			ds.SCtx().GetSessionVars().RaiseWarningWhenMPPEnforced("MPP mode may be blocked because you have set a hint to read table `" + hintTbl.TblName.O + "` from TiKV.")
 		}
 	}
-	if hintTbl := hintInfo.IfPreferTiFlash(alias); hintTbl != nil {
+	if hintTbl := hintInfo.IfPreferTiFlash(alias); hintTbl != nil || ds.SCtx().GetSessionVars().IsMPPEnforced() {
 		// `ds.PreferStoreType != 0`, which means there's a hint hit the both TiKV value and TiFlash value for table.
 		// We can't support read a table from two different storages, even partition table.
 		if ds.PreferStoreType != 0 {
@@ -535,7 +535,9 @@ func setPreferredStoreType(ds *logicalop.DataSource, hintInfo *h.PlanHints) {
 		for _, path := range ds.AllPossibleAccessPaths {
 			if path.StoreType == kv.TiFlash {
 				ds.PreferStoreType |= h.PreferTiFlash
-				ds.PreferPartitions[h.PreferTiFlash] = hintTbl.Partitions
+				if hintTbl != nil {
+					ds.PreferPartitions[h.PreferTiFlash] = hintTbl.Partitions
+				}
 				break
 			}
 		}