feat: Add new Remap interface to relations

plan/builders.go

@@ -71,46 +71,65 @@ type Builder interface {
 	// from the output.
 
 	Project(input Rel, exprs ...expr.Expression) (*ProjectRel, error)
+	// Deprecated: Use Project(...).Remap() instead.
 	ProjectRemap(input Rel, remap []int32, exprs ...expr.Expression) (*ProjectRel, error)
+	// Deprecated: Use AggregateColumns(...).Remap() instead.
 	AggregateColumnsRemap(input Rel, remap []int32, measures []AggRelMeasure, groupByCols ...int32) (*AggregateRel, error)
 	AggregateColumns(input Rel, measures []AggRelMeasure, groupByCols ...int32) (*AggregateRel, error)
+	// Deprecated: Use AggregateExprs(...).Remap() instead.
 	AggregateExprsRemap(input Rel, remap []int32, measures []AggRelMeasure, groups ...[]expr.Expression) (*AggregateRel, error)
 	AggregateExprs(input Rel, measures []AggRelMeasure, groups ...[]expr.Expression) (*AggregateRel, error)
+	// Deprecated: Use CreateTableAsSelect(...).Remap() instead.
 	CreateTableAsSelectRemap(input Rel, remap []int32, tableName []string, schema types.NamedStruct) (*NamedTableWriteRel, error)
 	CreateTableAsSelect(input Rel, tableName []string, schema types.NamedStruct) (*NamedTableWriteRel, error)
+	// Deprecated: Use Cross(...).Remap() instead.
 	CrossRemap(left, right Rel, remap []int32) (*CrossRel, error)
 	Cross(left, right Rel) (*CrossRel, error)
 	// FetchRemap constructs a fetch relation providing an offset (skipping some
 	// number of rows) and a count (restricting output to a maximum number of
 	// rows).  If count is FETCH_COUNT_ALL_RECORDS (-1) all records will be
 	// returned.  Similar to Fetch but allows for reordering and restricting the
 	// returned columns.
+	//
+	// Deprecated: Use Fetch(...).Remap() instead.
 	FetchRemap(input Rel, offset, count int64, remap []int32) (*FetchRel, error)
 	// Fetch constructs a fetch relation providing an offset (skipping some number of
 	// rows) and a count (restricting output to a maximum number of rows).  If count
 	// is FETCH_COUNT_ALL_RECORDS (-1) all records will be returned.
 	Fetch(input Rel, offset, count int64) (*FetchRel, error)
+	// Deprecated: Use Filter(...).Remap() instead.
 	FilterRemap(input Rel, condition expr.Expression, remap []int32) (*FilterRel, error)
 	Filter(input Rel, condition expr.Expression) (*FilterRel, error)
+	// Deprecated: Use JoinAndFilter(...).Remap() instead.
 	JoinAndFilterRemap(left, right Rel, condition, postJoinFilter expr.Expression, joinType JoinType, remap []int32) (*JoinRel, error)
+	// Deprecated: Use Fetch(...).Remap() instead.
 	JoinAndFilter(left, right Rel, condition, postJoinFilter expr.Expression, joinType JoinType) (*JoinRel, error)
+	// Deprecated: Use Join(...).Remap() instead.
 	JoinRemap(left, right Rel, condition expr.Expression, joinType JoinType, remap []int32) (*JoinRel, error)
 	Join(left, right Rel, condition expr.Expression, joinType JoinType) (*JoinRel, error)
+	// Deprecated: Use NamedScan(...).Remap() instead.
 	NamedScanRemap(tableName []string, schema types.NamedStruct, remap []int32) (*NamedTableReadRel, error)
 	NamedScan(tableName []string, schema types.NamedStruct) *NamedTableReadRel
+	// Deprecated: Use NamedWrite(...).Remap() instead.
 	NamedWriteRemap(input Rel, op WriteOp, tableName []string, schema types.NamedStruct, remap []int32) (*NamedTableWriteRel, error)
+	// NamedWrite performs the given write operation from the input relation over a named table.
+	NamedWrite(input Rel, op WriteOp, tableName []string, schema types.NamedStruct) (*NamedTableWriteRel, error)
 	// NamedInsert inserts data from the input relation into a named table.
 	NamedInsert(input Rel, tableName []string, schema types.NamedStruct) (*NamedTableWriteRel, error)
 	// NamedDelete deletes rows from a specified named table based on the
 	// provided input relation, which typically includes conditions that filter
 	// the rows to delete.
 	NamedDelete(input Rel, tableName []string, schema types.NamedStruct) (*NamedTableWriteRel, error)
+	// Deprecated: Use VirtualTable(...).Remap() instead.
 	VirtualTableRemap(fields []string, remap []int32, values ...expr.StructLiteralValue) (*VirtualTableReadRel, error)
 	VirtualTable(fields []string, values ...expr.StructLiteralValue) (*VirtualTableReadRel, error)
+	// Deprecated: Use VirtualTableFromExpr(...).Remap() instead.
 	VirtualTableFromExprRemap(fieldNames []string, remap []int32, values ...expr.VirtualTableExpressionValue) (*VirtualTableReadRel, error)
 	VirtualTableFromExpr(fieldNames []string, values ...expr.VirtualTableExpressionValue) (*VirtualTableReadRel, error)
+	// Deprecated: Use Sort(...).Remap() instead.
 	SortRemap(input Rel, remap []int32, sorts ...expr.SortField) (*SortRel, error)
 	Sort(input Rel, sorts ...expr.SortField) (*SortRel, error)
+	// Deprecated: Use Set(...).Remap() instead.
 	SetRemap(op SetOp, remap []int32, inputs ...Rel) (*SetRel, error)
 	Set(op SetOp, inputs ...Rel) (*SetRel, error)
 
@@ -487,12 +506,16 @@ func (b *builder) NamedWriteRemap(input Rel, op WriteOp, tableName []string, sch
 	}, nil
 }
 
+func (b *builder) NamedWrite(input Rel, op WriteOp, tableName []string, schema types.NamedStruct) (*NamedTableWriteRel, error) {
+	return b.NamedWriteRemap(input, op, tableName, schema, nil)
+}
+
 func (b *builder) NamedInsert(input Rel, tableName []string, schema types.NamedStruct) (*NamedTableWriteRel, error) {
-	return b.NamedWriteRemap(input, WriteOpInsert, tableName, schema, nil)
+	return b.NamedWrite(input, WriteOpInsert, tableName, schema)
 }
 
 func (b *builder) NamedDelete(input Rel, tableName []string, schema types.NamedStruct) (*NamedTableWriteRel, error) {
-	return b.NamedWriteRemap(input, WriteOpDelete, tableName, schema, nil)
+	return b.NamedWrite(input, WriteOpDelete, tableName, schema)
 }
 
 func (b *builder) NamedScanRemap(tableName []string, schema types.NamedStruct, remap []int32) (*NamedTableReadRel, error) {

plan/common.go

@@ -47,7 +47,16 @@ func (rc *RelCommon) remap(initial types.RecordType) types.RecordType {
 	return *types.NewRecordTypeFromTypes(outTypes)
 }
 
-func (rc *RelCommon) OutputMapping() []int32 { return rc.mapping }
+func (rc *RelCommon) OutputMapping() []int32 {
+	// Make a copy of the output mapping to prevent accidental modification.
+	mapCopy := make([]int32, len(rc.mapping))
+	copy(mapCopy, rc.mapping)
+	return mapCopy
+}
+
+func (rc *RelCommon) setMapping(mapping []int32) {
+	rc.mapping = mapping
+}
 
 func (rc *RelCommon) GetAdvancedExtension() *extensions.AdvancedExtension {
 	return rc.advExtension

plan/plan.go

@@ -255,6 +255,8 @@ type RewriteFunc func(expr.Expression) (expr.Expression, error)
 // It contains the common functionality between the different relations
 // and should be type switched to determine which relation type it actually
 // is for evaluation.
+//
+// All the exported methods in this interface should be considered constant.
 type Rel interface {
 	// Hint returns a set of changes to the operation which can influence
 	// efficiency and performance but should not impact correctness.
@@ -271,6 +273,21 @@ type Rel interface {
 	// result should be 3 columns consisting of the 5th, 2nd and 1st
 	// output columns from the underlying relation.
 	OutputMapping() []int32
+
+	// Remap modifies the current relation by applying the provided
+	// mapping to the current relation.  Typically used to remove any
+	// unneeded columns or provide them in a different order.  If there
+	// already is a mapping on this relation, this provides mapping over
+	// the current mapping.
+	//
+	// If any column numbers specified are outside the currently available
+	// input range an error is returned and the mapping is left unchanged.
+	Remap(mapping ...int32) (Rel, error)
+
+	// setMapping sets the current mapping and is for internal use.
+	// It performs no checks.  End users should call Remap() instead.
+	setMapping(mapping []int32)
+
 	// directOutputSchema returns the output record type of the underlying
 	// relation as a struct type.  Mapping is not applied.
 	directOutputSchema() types.RecordType