SQL failed with "ERROR 1105 (HY000): runtime error: invalid memory address or nil pointer dereference" when tidb_enable_inl_join_inner_multi_pattern is ON

[joechenrh]

Bug Report

1. Minimal reproduce step (Required)

set GLOBAL tidb_enable_inl_join_inner_multi_pattern='ON';
create table t1(col_1 int, index idx_1(col_1));
create table t2(col_1 int, col_2 int, index idx_2(col_1));

select /*+ inl_join(tmp) */ * from t1 inner join (select col_1, group_concat(col_2) from t2 group by col_1) tmp on t1.col_1 = tmp.col_1;

2. What did you expect to see? (Required)

Run successfully

3. What did you see instead (Required)

[2024/08/02 15:51:11.915 +08:00] [ERROR] [conn.go:1040] ["connection running loop panic"] [conn=2097156] [session_alias=] [lastSQL="select /*+ inl_join(tmp) */ * from t1 inner join (select col_1, group_concat(col_2) from t2 group by col_1) tmp on t1.col_1 = tmp.col_1"] [err="runtime error: invalid memory address or nil pointer dereference"] [stack="github.com/pingcap/tidb/pkg/server.(*clientConn).Run.func1\n\t/Users/joechenrh/code/tidb-fix/pkg/server/conn.go:1043\nruntime.gopanic
/Users/joechenrh/deps/go/src/runtime/panic.go:770\ngithub.com/pingcap/tidb/pkg/executor.(*Compiler).Compile.func1
/Users/joechenrh/code/tidb-fix/pkg/executor/compiler.go:57\nruntime.gopanic
/Users/joechenrh/deps/go/src/runtime/panic.go:770\nruntime.panicmem
/Users/joechenrh/deps/go/src/runtime/panic.go:261\nruntime.sigpanic
/Users/joechenrh/deps/go/src/runtime/signal_unix.go:881\ngithub.com/pingcap/tidb/pkg/planner/property.(*PhysicalProperty).CloneEssentialFields
/Users/joechenrh/code/tidb-fix/pkg/planner/property/physical_property.go:366\ngithub.com/pingcap/tidb/pkg/planner/core.InjectProjBelowAgg
/Users/joechenrh/code/tidb-fix/pkg/planner/core/rule_inject_extra_projection.go:208\ngithub.com/pingcap/tidb/pkg/planner/core.(*projInjector).inject
/Users/joechenrh/code/tidb-fix/pkg/planner/core/rule_inject_extra_projection.go:68\ngithub.com/pingcap/tidb/pkg/planner/core.(*projInjector).inject\n\t/Users/joechenrh/code/tidb-fix/pkg/planner/core/rule_inject_extra_projection.go:58\ngithub.com/pingcap/tidb/pkg/planner/core.(*projInjector).inject
/Users/joechenrh/code/tidb-fix/pkg/planner/core/rule_inject_extra_projection.go:58\ngithub.com/pingcap/tidb/pkg/planner/core.InjectExtraProjection
/Users/joechenrh/code/tidb-fix/pkg/planner/core/rule_inject_extra_projection.go:45\ngithub.com/pingcap/tidb/pkg/planner/core.postOptimize
/Users/joechenrh/code/tidb-fix/pkg/planner/core/optimizer.go:424\ngithub.com/pingcap/tidb/pkg/planner/core.doOptimize
/Users/joechenrh/code/tidb-fix/pkg/planner/core/optimizer.go:312\ngithub.com/pingcap/tidb/pkg/planner/core.DoOptimize
/Users/joechenrh/code/tidb-fix/pkg/planner/core/optimizer.go:355\ngithub.com/pingcap/tidb/pkg/planner.optimize
/Users/joechenrh/code/tidb-fix/pkg/planner/optimize.go:525\ngithub.com/pingcap/tidb/pkg/planner.Optimize
/Users/joechenrh/code/tidb-fix/pkg/planner/optimize.go:356\ngithub.com/pingcap/tidb/pkg/executor.(*Compiler).Compile
/Users/joechenrh/code/tidb-fix/pkg/executor/compiler.go:99\ngithub.com/pingcap/tidb/pkg/session.(*session).ExecuteStmt
/Users/joechenrh/code/tidb-fix/pkg/session/session.go:2097\ngithub.com/pingcap/tidb/pkg/server.(*TiDBContext).ExecuteStmt
/Users/joechenrh/code/tidb-fix/pkg/server/driver_tidb.go:291\ngithub.com/pingcap/tidb/pkg/server.(*clientConn).handleStmt
/Users/joechenrh/code/tidb-fix/pkg/server/conn.go:2047\ngithub.com/pingcap/tidb/pkg/server.(*clientConn).handleQuery
/Users/joechenrh/code/tidb-fix/pkg/server/conn.go:1801\ngithub.com/pingcap/tidb/pkg/server.(*clientConn).dispatch
/Users/joechenrh/code/tidb-fix/pkg/server/conn.go:1375\ngithub.com/pingcap/tidb/pkg/server.(*clientConn).Run
/Users/joechenrh/code/tidb-fix/pkg/server/conn.go:1141\ngithub.com/pingcap/tidb/pkg/server.(*Server).onConn
/Users/joechenrh/code/tidb-fix/pkg/server/server.go:740"]

4. What is your TiDB version? (Required)

[joechenrh]

tidb/pkg/planner/core/exhaust_physical_plans.go

Lines 1396 to 1428 in 5a44248

	var aggTask base.Task
	// build stream agg and change ds keep order to true
	if preferStream {
	newGbyItems := make([]expression.Expression, len(la.GroupByItems))
	copy(newGbyItems, la.GroupByItems)
	newAggFuncs := make([]*aggregation.AggFuncDesc, len(la.AggFuncs))
	copy(newAggFuncs, la.AggFuncs)
	streamAgg := basePhysicalAgg{
	GroupByItems: newGbyItems,
	AggFuncs: newAggFuncs,
	}.initForStream(la.SCtx(), la.StatsInfo(), la.QueryBlockOffset(), nil)
	streamAgg.SetSchema(la.Schema().Clone())
	// change to keep order for index scan and dsCopTask
	if dsCopTask.indexPlan != nil {
	// get the index scan from dsCopTask.indexPlan
	physicalIndexScan, _ := dsCopTask.indexPlan.(*PhysicalIndexScan)
	if physicalIndexScan == nil && len(dsCopTask.indexPlan.Children()) == 1 {
	physicalIndexScan, _ = dsCopTask.indexPlan.Children()[0].(*PhysicalIndexScan)
	}
	if physicalIndexScan != nil {
	physicalIndexScan.KeepOrder = true
	dsCopTask.keepOrder = true
	aggTask = streamAgg.Attach2Task(dsCopTask)
	}
	}
	}
	// build hash agg, when the stream agg is illegal such as the order by prop is not matched
	if aggTask == nil {
	physicalHashAgg := NewPhysicalHashAgg(la, la.StatsInfo(), nil)
	physicalHashAgg.SetSchema(la.Schema().Clone())
	aggTask = physicalHashAgg.Attach2Task(dsCopTask)
	}

For those aggregation functions that cannot be pushed down, their PhysicalProperty is not set.

Add a default property &property.PhysicalProperty{ExpectedCnt: math.MaxFloat64} like it does in newPartialAggregate() seems work.

[joechenrh]

Another panic

select /*+ inl_join(tmp) */ * from t1 inner join (select col_1, group_concat(distinct col_2 order by col_2) from t2 group by col_1) tmp on t1.col_1 = tmp.col_1;

PhysicalProperty is not set in this conditional branch too.

tidb/pkg/planner/core/exhaust_physical_plans.go

Lines 1352 to 1356 in 5a44248

	if !canPushAggToCop {
	result := dsCopTask.ConvertToRootTask(ds.SCtx()).(*RootTask)
	result.SetPlan(constructInnerByZippedChildren(wrapper.zippedChildren, result.GetPlan()))
	return result
	}