Class: PushdownSelections

Defined in: packages/core/src/optimizer/rules/selection-pushdown.ts:54

Pushes down selection predicates through the query plan, so that they can be applied as early as possible.

Implements

• PatternRule<Selection, PushdownSelectionsBindings>

Constructors

Constructor

new PushdownSelections(db): PushdownSelections

Defined in: packages/core/src/optimizer/rules/selection-pushdown.ts:78

Parameters

Parameter	Type	Description
db	DortDBAsFriend	Internal database interface.

Returns

PushdownSelections

Properties

alwaysSwap

alwaysSwap: (...args) => TupleOperatorWithSource[]

Defined in: packages/core/src/optimizer/rules/selection-pushdown.ts:62

Operator classes whose selection can always be pushed below them (e.g. OrderBy, Distinct).

Parameters

Parameter	Type
...args	any[]

Returns

TupleOperatorWithSource

---

db

protected db: DortDBAsFriend

Defined in: packages/core/src/optimizer/rules/selection-pushdown.ts:80

Internal database interface.

---

operator

operator: typeof Selection = Selection

Defined in: packages/core/src/optimizer/rules/selection-pushdown.ts:58

The operator this rule starts matching at.

Implementation of

PatternRule.operator

---

renameCheckerVmap

protected renameCheckerVmap: Record<string, AttributeRenameChecker>

Defined in: packages/core/src/optimizer/rules/selection-pushdown.ts:76

Per-language attribute-rename-checker visitor instances.

---

renamerVmap

protected renamerVmap: Record<string, AttributeRenamer>

Defined in: packages/core/src/optimizer/rules/selection-pushdown.ts:74

Per-language attribute-renamer visitor instances.

---

setOps

setOps: (...args) => BranchedOperator[]

Defined in: packages/core/src/optimizer/rules/selection-pushdown.ts:68

Set-operation operator classes through which selections are duplicated to both branches.

Parameters

Parameter	Type
...args	any[]

Returns

BranchedOperator

---

tdepsVmap

protected tdepsVmap: Record<string, TransitiveDependencies>

Defined in: packages/core/src/optimizer/rules/selection-pushdown.ts:72

Per-language transitive-dependency visitor instances.

Methods

checkProjection()

protected checkProjection(s, p, toRenameContainer?): boolean

Defined in: packages/core/src/optimizer/rules/selection-pushdown.ts:558

Returns true if selection s can be pushed through projection p; adds s to toRenameContainer when a rename is also needed.

Parameters

Parameter	Type
s	Selection
p	Projection
toRenameContainer?	Set<Selection>

Returns

boolean

---

cloneSelection()

protected cloneSelection(s): Selection

Defined in: packages/core/src/optimizer/rules/selection-pushdown.ts:550

Returns a shallow clone of s with its own schema copy.

Parameters

Parameter	Type
s	Selection

Returns

Selection

---

getSelectionDeps()

protected getSelectionDeps(s): IdSet

Defined in: packages/core/src/optimizer/rules/selection-pushdown.ts:212

Returns the set of identifiers that the selection's condition transitively depends on.

Parameters

Parameter	Type
s	Selection

Returns

IdSet

---

match()

match(node): PatternRuleMatchResult<PushdownSelectionsBindings>

Defined in: packages/core/src/optimizer/rules/selection-pushdown.ts:90

Matches the given plan operator against this rule.

Parameters

Parameter	Type	Description
node	Selection	The plan operator to match.

Returns

PatternRuleMatchResult<PushdownSelectionsBindings>

Implementation of

PatternRule.match

---

matchGroupBy()

protected matchGroupBy(bindings): PatternRuleMatchResult<PushdownSelectionsBindings>

Defined in: packages/core/src/optimizer/rules/selection-pushdown.ts:132

Returns match bindings when at least one selection depends only on group-by keys.

Parameters

Parameter	Type
bindings	PushdownSelectionsBindings

Returns

PatternRuleMatchResult<PushdownSelectionsBindings>

---

matchJoins()

protected matchJoins(bindings): PatternRuleMatchResult<PushdownSelectionsBindings>

Defined in: packages/core/src/optimizer/rules/selection-pushdown.ts:147

Returns match bindings when at least one selection can be pushed to one side of a join.

Parameters

Parameter	Type
bindings	PushdownSelectionsBindings

Returns

PatternRuleMatchResult<PushdownSelectionsBindings>

---

matchProjection()

protected matchProjection(bindings): PatternRuleMatchResult<PushdownSelectionsBindings>

Defined in: packages/core/src/optimizer/rules/selection-pushdown.ts:179

Returns match bindings when at least one selection can be pushed through the projection.

Parameters

Parameter	Type
bindings	PushdownSelectionsBindings

Returns

PatternRuleMatchResult<PushdownSelectionsBindings>

---

matchProjectionConcat()

protected matchProjectionConcat(bindings): PatternRuleMatchResult<PushdownSelectionsBindings>

Defined in: packages/core/src/optimizer/rules/selection-pushdown.ts:163

Returns match bindings when at least one selection can be pushed into the source or mapping branch of a projection concat.

Parameters

Parameter	Type
bindings	PushdownSelectionsBindings

Returns

PatternRuleMatchResult<PushdownSelectionsBindings>

---

matchSetOp()

protected matchSetOp(bindings): PatternRuleMatchResult<PushdownSelectionsBindings>

Defined in: packages/core/src/optimizer/rules/selection-pushdown.ts:191

Returns match bindings when at least one selection can be pushed through a set operation.

Parameters

Parameter	Type
bindings	PushdownSelectionsBindings

Returns

PatternRuleMatchResult<PushdownSelectionsBindings>

---

pushSelectionsUnder()

protected pushSelectionsUnder<Key, Op>(selections, key, source): void

Defined in: packages/core/src/optimizer/rules/selection-pushdown.ts:582

Rewires selections so they sit between source and source[key], updating parent references and schemas.

Type Parameters

Type Parameter
Key extends string
Op extends PlanTupleOperator & Record<Key, PlanTupleOperator>

Parameters

Parameter	Type
selections	Selection[]
key	Key
source	Op

Returns

void

---

tranformSetOp()

protected tranformSetOp(source, selections): Selection | BranchedOperator<PlanTupleOperator>

Defined in: packages/core/src/optimizer/rules/selection-pushdown.ts:328

Duplicates the selection stack into both branches of the set operation.

Parameters

Parameter	Type
source	BranchedOperator<PlanTupleOperator>
selections	Selection[]

Returns

Selection | BranchedOperator<PlanTupleOperator>

---

transform()

transform(node, bindings): PlanOperator

Defined in: packages/core/src/optimizer/rules/selection-pushdown.ts:216

Transforms the given plan operator using the provided bindings.

Parameters

Parameter	Type	Description
node	Selection	The plan operator to transform.
bindings	PushdownSelectionsBindings	The bindings to use for the transformation.

Returns

PlanOperator

Implementation of

PatternRule.transform

---

transformBasic()

protected transformBasic(source, first, last): TupleOperatorWithSource

Defined in: packages/core/src/optimizer/rules/selection-pushdown.ts:254

Moves the selection stack below source, which is an operator that simply wraps a single child.

Parameters

Parameter	Type
source	TupleOperatorWithSource
first	Selection
last	Selection

Returns

TupleOperatorWithSource

---

transformGroupBy()

protected transformGroupBy(source, selections): Selection | GroupBy

Defined in: packages/core/src/optimizer/rules/selection-pushdown.ts:267

Partitions selections into those that can be pushed below source and those that must stay above it.

Parameters

Parameter	Type
source	GroupBy
selections	Selection[]

Returns

Selection | GroupBy

---

transformJoin()

protected transformJoin(source, selections): Selection | CartesianProduct

Defined in: packages/core/src/optimizer/rules/selection-pushdown.ts:459

Routes each selection to the left branch, right branch, or leaves it above the join.

Parameters

Parameter	Type
source	CartesianProduct
selections	Selection[]

Returns

Selection | CartesianProduct

---

transformProjection()

protected transformProjection(source, selections): Projection | Selection

Defined in: packages/core/src/optimizer/rules/selection-pushdown.ts:410

Pushes selections that can pass through source below it, renaming their conditions as needed.

Parameters

Parameter	Type
source	Projection
selections	Selection[]

Returns

Projection | Selection

---

transformProjectionConcat()

protected transformProjectionConcat(source, selections): Selection | ProjectionConcat

Defined in: packages/core/src/optimizer/rules/selection-pushdown.ts:506

Pushes selections into the source or mapping branch of a projection concat where possible.

Parameters

Parameter	Type
source	ProjectionConcat
selections	Selection[]

Returns

Selection | ProjectionConcat