planner: classify logical expand logic into a separate file for later pkg move.

pkg/planner/core/exhaust_physical_plans.go

@@ -2589,10 +2589,7 @@ func choosePartitionKeys(keys []*property.MPPPartitionColumn, matches []int) []*
 	return newKeys
 }
 
-// ExhaustPhysicalPlans enumerate all the possible physical plan for expand operator.
-// The second boolean means whether we should resort to enforcer to satisfy prop requirement.
-// false means we should, while true means we should not.
-func (p *LogicalExpand) ExhaustPhysicalPlans(prop *property.PhysicalProperty) ([]base.PhysicalPlan, bool, error) {
+func exhaustPhysicalPlans4LogicalExpand(p *LogicalExpand, prop *property.PhysicalProperty) ([]base.PhysicalPlan, bool, error) {
 	// under the mpp task type, if the sort item is not empty, refuse it, cause expanded data doesn't support any sort items.
 	if !prop.IsSortItemEmpty() {
 		// false, meaning we can add a sort enforcer.

pkg/planner/core/logical_expand.go

@@ -19,10 +19,15 @@ import (
 	"fmt"
 
 	"github.com/pingcap/tidb/pkg/expression"
+	"github.com/pingcap/tidb/pkg/planner/core/base"
 	"github.com/pingcap/tidb/pkg/planner/core/operator/logicalop"
 	fd "github.com/pingcap/tidb/pkg/planner/funcdep"
+	"github.com/pingcap/tidb/pkg/planner/property"
+	"github.com/pingcap/tidb/pkg/planner/util/optimizetrace"
+	"github.com/pingcap/tidb/pkg/planner/util/optimizetrace/logicaltrace"
 	"github.com/pingcap/tidb/pkg/types"
 	"github.com/pingcap/tidb/pkg/util/dbterror/plannererrors"
+	"github.com/pingcap/tidb/pkg/util/plancodec"
 	"github.com/pingcap/tipb/go-tipb"
 )
 
@@ -59,13 +64,85 @@ type LogicalExpand struct {
 	GPosName *types.FieldName
 }
 
-// ExtractFD implements the logical plan interface, extracting the FD from bottom up.
-func (p *LogicalExpand) ExtractFD() *fd.FDSet {
-	// basically extract the children's fdSet.
-	return p.LogicalSchemaProducer.ExtractFD()
+// Init initializes LogicalProjection.
+func (p LogicalExpand) Init(ctx base.PlanContext, offset int) *LogicalExpand {
+	p.BaseLogicalPlan = logicalop.NewBaseLogicalPlan(ctx, plancodec.TypeExpand, &p, offset)
+	return &p
+}
+
+// *************************** start implementation of logicalPlan interface ***************************
+
+// HashCode inherits BaseLogicalPlan.LogicalPlan.<0th> implementation.
+
+// PredicatePushDown implements base.LogicalPlan.<1st> interface.
+func (p *LogicalExpand) PredicatePushDown(predicates []expression.Expression, opt *optimizetrace.LogicalOptimizeOp) (ret []expression.Expression, retPlan base.LogicalPlan) {
+	// Note that, grouping column related predicates can't be pushed down, since grouping column has nullability change after Expand OP itself.
+	// condition related with grouping column shouldn't be pushed down through it.
+	// currently, since expand is adjacent to aggregate, any filter above aggregate wanted to be push down through expand only have two cases:
+	// 		1. agg function related filters. (these condition is always above aggregate)
+	// 		2. group-by item related filters. (there condition is always related with grouping sets columns, which can't be pushed down)
+	// As a whole, we banned all the predicates pushing-down logic here that remained in Expand OP, and constructing a new selection above it if any.
+	remained, child := p.BaseLogicalPlan.PredicatePushDown(nil, opt)
+	return append(remained, predicates...), child
+}
+
+// PruneColumns implement the base.LogicalPlan.<2nd> interface.
+// logicExpand is built in the logical plan building phase, where all the column prune is not done yet. So the
+// expand projection expressions is meaningless if it built at that time. (we only maintain its schema, while
+// the level projection expressions construction is left to the last logical optimize rule)
+//
+// so when do the rule_column_pruning here, we just prune the schema is enough.
+func (p *LogicalExpand) PruneColumns(parentUsedCols []*expression.Column, opt *optimizetrace.LogicalOptimizeOp) (base.LogicalPlan, error) {
+	// Expand need those extra redundant distinct group by columns projected from underlying projection.
+	// distinct GroupByCol must be used by aggregate above, to make sure this, append DistinctGroupByCol again.
+	parentUsedCols = append(parentUsedCols, p.DistinctGroupByCol...)
+	used := expression.GetUsedList(p.SCtx().GetExprCtx().GetEvalCtx(), parentUsedCols, p.Schema())
+	prunedColumns := make([]*expression.Column, 0)
+	for i := len(used) - 1; i >= 0; i-- {
+		if !used[i] {
+			prunedColumns = append(prunedColumns, p.Schema().Columns[i])
+			p.Schema().Columns = append(p.Schema().Columns[:i], p.Schema().Columns[i+1:]...)
+			p.SetOutputNames(append(p.OutputNames()[:i], p.OutputNames()[i+1:]...))
+		}
+	}
+	logicaltrace.AppendColumnPruneTraceStep(p, prunedColumns, opt)
+	// Underlying still need to keep the distinct group by columns and parent used columns.
+	var err error
+	p.Children()[0], err = p.Children()[0].PruneColumns(parentUsedCols, opt)
+	if err != nil {
+		return nil, err
+	}
+	return p, nil
+}
+
+// FindBestTask inherits BaseLogicalPlan.LogicalPlan.<3rd> implementation.
+
+// BuildKeyInfo inherits BaseLogicalPlan.LogicalPlan.<4th> implementation.
+
+// PushDownTopN inherits BaseLogicalPlan.LogicalPlan.<5th> implementation.
+
+// DeriveTopN inherits BaseLogicalPlan.LogicalPlan.<6th> implementation.
+
+// PredicateSimplification inherits BaseLogicalPlan.LogicalPlan.<7th> implementation.
+
+// ConstantPropagation inherits BaseLogicalPlan.LogicalPlan.<8th> implementation.
+
+// PullUpConstantPredicates inherits BaseLogicalPlan.LogicalPlan.<9th> implementation.
+
+// RecursiveDeriveStats inherits BaseLogicalPlan.LogicalPlan.<10th> implementation.
+
+// DeriveStats inherits BaseLogicalPlan.LogicalPlan.<11th> implementation.
+
+// ExtractColGroups inherits BaseLogicalPlan.LogicalPlan.<12th> implementation.
+
+// PreparePossibleProperties inherits BaseLogicalPlan.LogicalPlan.<13th> implementation.
+
+// ExhaustPhysicalPlans implements base.LogicalPlan.<14th> interface.
+func (p *LogicalExpand) ExhaustPhysicalPlans(prop *property.PhysicalProperty) ([]base.PhysicalPlan, bool, error) {
+	return exhaustPhysicalPlans4LogicalExpand(p, prop)
 }
 
-// ExtractCorrelatedCols implements LogicalPlan interface.
+// ExtractCorrelatedCols implements base.LogicalPlan.<15th> interface.
 func (p *LogicalExpand) ExtractCorrelatedCols() []*expression.CorrelatedColumn {
 	corCols := make([]*expression.CorrelatedColumn, 0, len(p.LevelExprs[0]))
 	for _, lExpr := range p.LevelExprs {
@@ -76,6 +153,30 @@ func (p *LogicalExpand) ExtractCorrelatedCols() []*expression.CorrelatedColumn {
 	return corCols
 }
 
+// MaxOneRow inherits BaseLogicalPlan.LogicalPlan.<16th> implementation.
+
+// Children inherits BaseLogicalPlan.LogicalPlan.<17th> implementation.
+
+// SetChildren inherits BaseLogicalPlan.LogicalPlan.<18th> implementation.
+
+// SetChild inherits BaseLogicalPlan.LogicalPlan.<19th> implementation.
+
+// RollBackTaskMap inherits BaseLogicalPlan.LogicalPlan.<20th> implementation.
+
+// CanPushToCop inherits BaseLogicalPlan.LogicalPlan.<21st> implementation.
+
+// ExtractFD implements the base.LogicalPlan.<22nd> interface, extracting the FD from bottom up.
+func (p *LogicalExpand) ExtractFD() *fd.FDSet {
+	// basically extract the children's fdSet.
+	return p.LogicalSchemaProducer.ExtractFD()
+}
+
+// GetBaseLogicalPlan inherits BaseLogicalPlan.LogicalPlan.<23rd> implementation.
+
+// ConvertOuterToInnerJoin inherits BaseLogicalPlan.LogicalPlan.<24th> implementation.
+
+// *************************** end implementation of logicalPlan interface ***************************
+
 // GetUsedCols extracts all of the Columns used by proj.
 func (*LogicalExpand) GetUsedCols() (usedCols []*expression.Column) {
 	// be careful that, expand OP itself, shouldn't output its own used cols, because

pkg/planner/core/logical_initialize.go

@@ -13,15 +13,3 @@
 // limitations under the License.
 
 package core
-
-import (
-	"github.com/pingcap/tidb/pkg/planner/core/base"
-	"github.com/pingcap/tidb/pkg/planner/core/operator/logicalop"
-	"github.com/pingcap/tidb/pkg/util/plancodec"
-)
-
-// Init initializes LogicalProjection.
-func (p LogicalExpand) Init(ctx base.PlanContext, offset int) *LogicalExpand {
-	p.BaseLogicalPlan = logicalop.NewBaseLogicalPlan(ctx, plancodec.TypeExpand, &p, offset)
-	return &p
-}

pkg/planner/core/rule_column_pruning.go

@@ -39,35 +39,6 @@ func (*columnPruner) optimize(_ context.Context, lp base.LogicalPlan, opt *optim
 	return lp, planChanged, nil
 }
 
-// PruneColumns implement the Expand OP's column pruning logic.
-// logicExpand is built in the logical plan building phase, where all the column prune is not done yet. So the
-// expand projection expressions is meaningless if it built at that time. (we only maintain its schema, while
-// the level projection expressions construction is left to the last logical optimize rule)
-//
-// so when do the rule_column_pruning here, we just prune the schema is enough.
-func (p *LogicalExpand) PruneColumns(parentUsedCols []*expression.Column, opt *optimizetrace.LogicalOptimizeOp) (base.LogicalPlan, error) {
-	// Expand need those extra redundant distinct group by columns projected from underlying projection.
-	// distinct GroupByCol must be used by aggregate above, to make sure this, append DistinctGroupByCol again.
-	parentUsedCols = append(parentUsedCols, p.DistinctGroupByCol...)
-	used := expression.GetUsedList(p.SCtx().GetExprCtx().GetEvalCtx(), parentUsedCols, p.Schema())
-	prunedColumns := make([]*expression.Column, 0)
-	for i := len(used) - 1; i >= 0; i-- {
-		if !used[i] {
-			prunedColumns = append(prunedColumns, p.Schema().Columns[i])
-			p.Schema().Columns = append(p.Schema().Columns[:i], p.Schema().Columns[i+1:]...)
-			p.SetOutputNames(append(p.OutputNames()[:i], p.OutputNames()[i+1:]...))
-		}
-	}
-	logicaltrace.AppendColumnPruneTraceStep(p, prunedColumns, opt)
-	// Underlying still need to keep the distinct group by columns and parent used columns.
-	var err error
-	p.Children()[0], err = p.Children()[0].PruneColumns(parentUsedCols, opt)
-	if err != nil {
-		return nil, err
-	}
-	return p, nil
-}
-
 func pruneByItems(p base.LogicalPlan, old []*util.ByItems, opt *optimizetrace.LogicalOptimizeOp) (byItems []*util.ByItems,
 	parentUsedCols []*expression.Column) {
 	prunedByItems := make([]*util.ByItems, 0)

pkg/planner/core/rule_predicate_push_down.go

@@ -100,18 +100,6 @@ func BreakDownPredicates(p *LogicalProjection, predicates []expression.Expressio
 	return canBePushed, canNotBePushed
 }
 
-// PredicatePushDown implements base.LogicalPlan PredicatePushDown interface.
-func (p *LogicalExpand) PredicatePushDown(predicates []expression.Expression, opt *optimizetrace.LogicalOptimizeOp) (ret []expression.Expression, retPlan base.LogicalPlan) {
-	// Note that, grouping column related predicates can't be pushed down, since grouping column has nullability change after Expand OP itself.
-	// condition related with grouping column shouldn't be pushed down through it.
-	// currently, since expand is adjacent to aggregate, any filter above aggregate wanted to be push down through expand only have two cases:
-	// 		1. agg function related filters. (these condition is always above aggregate)
-	// 		2. group-by item related filters. (there condition is always related with grouping sets columns, which can't be pushed down)
-	// As a whole, we banned all the predicates pushing-down logic here that remained in Expand OP, and constructing a new selection above it if any.
-	remained, child := p.BaseLogicalPlan.PredicatePushDown(nil, opt)
-	return append(remained, predicates...), child
-}
-
 // DeriveOtherConditions given a LogicalJoin, check the OtherConditions to see if we can derive more
 // conditions for left/right child pushdown.
 func DeriveOtherConditions(