planner: merge FullSchema and FullNames of subplans when rewriting "in (subquery)" to inner join (#54334)

[ti-chi-bot]

This is an automated cherry-pick of #54334

What problem does this PR solve?

Issue Number: close #53766

Problem Summary:

What changed and how does it work?

Merge FullSchema and FullNames of subplans when rewring "in (subquery)" to inner join, which will be used to rewrite fields when using natural join.

tidb/pkg/planner/core/expression_rewriter.go

Lines 2469 to 2485 in 4381699

	func findFieldNameFromNaturalUsingJoin(p base.LogicalPlan, v *ast.ColumnName) (col *expression.Column, name *types.FieldName, err error) {
	switch x := p.(type) {
	case *LogicalLimit, *LogicalSelection, *LogicalTopN, *LogicalSort, *LogicalMaxOneRow:
	return findFieldNameFromNaturalUsingJoin(p.Children()[0], v)
	case *LogicalJoin:
	if x.FullSchema != nil {
	idx, err := expression.FindFieldName(x.FullNames, v)
	if err != nil {
	return nil, nil, err
	}
	if idx >= 0 {
	return x.FullSchema.Columns[idx], x.FullNames[idx], nil
	}
	}
	}
	return nil, nil, nil
	}

The merging code I referenced was from the code in buildJoin as follows:

tidb/pkg/planner/core/logical_plan_builder.go

Lines 985 to 1026 in 4381699

	// Merge sub-plan's FullSchema into this join plan.
	// Please read the comment of LogicalJoin.FullSchema for the details.
	var (
	lFullSchema, rFullSchema *expression.Schema
	lFullNames, rFullNames types.NameSlice
	)
	if left, ok := leftPlan.(*LogicalJoin); ok && left.FullSchema != nil {
	lFullSchema = left.FullSchema
	lFullNames = left.FullNames
	} else {
	lFullSchema = leftPlan.Schema()
	lFullNames = leftPlan.OutputNames()
	}
	if right, ok := rightPlan.(*LogicalJoin); ok && right.FullSchema != nil {
	rFullSchema = right.FullSchema
	rFullNames = right.FullNames
	} else {
	rFullSchema = rightPlan.Schema()
	rFullNames = rightPlan.OutputNames()
	}
	if joinNode.Tp == ast.RightJoin {
	// Make sure lFullSchema means outer full schema and rFullSchema means inner full schema.
	lFullSchema, rFullSchema = rFullSchema, lFullSchema
	lFullNames, rFullNames = rFullNames, lFullNames
	}
	joinPlan.FullSchema = expression.MergeSchema(lFullSchema, rFullSchema)
	// Clear NotNull flag for the inner side schema if it's an outer join.
	if joinNode.Tp == ast.LeftJoin || joinNode.Tp == ast.RightJoin {
	resetNotNullFlag(joinPlan.FullSchema, lFullSchema.Len(), joinPlan.FullSchema.Len())
	}
	// Merge sub-plan's FullNames into this join plan, similar to the FullSchema logic above.
	joinPlan.FullNames = make([]*types.FieldName, 0, len(lFullNames)+len(rFullNames))
	for _, lName := range lFullNames {
	name := *lName
	joinPlan.FullNames = append(joinPlan.FullNames, &name)
	}
	for _, rName := range rFullNames {
	name := *rName
	joinPlan.FullNames = append(joinPlan.FullNames, &name)
	}

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No need to test

  • I checked and no code files have been changed.

Side effects

• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Breaking backward compatibility

Documentation

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features
• Changes MySQL compatibility

Release note

Please refer to Release Notes Language Style Guide to write a quality release note.

None

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@ti-chi-bot: The following tests failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
idc-jenkins-ci-tidb/check_dev_2	4065837	link	true	/test check-dev2
idc-jenkins-ci-tidb/check_dev	4065837	link	true	/test check-dev
idc-jenkins-ci-tidb/build	4065837	link	true	/test build
idc-jenkins-ci-tidb/mysql-test	4065837	link	true	/test mysql-test
idc-jenkins-ci-tidb/unit-test	4065837	link	true	/test unit-test

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