Class: MergeProjections

Defined in: packages/core/src/optimizer/rules/merge-projections.ts:30

Merge multiple projections into a single projection.

Implements

• PatternRule<Projection, MergeProjectionsBindings>

Constructors

Constructor

new MergeProjections(db): MergeProjections

Defined in: packages/core/src/optimizer/rules/merge-projections.ts:42

Parameters

Parameter	Type	Description
db	DortDBAsFriend	Internal database interface.

Returns

MergeProjections

Properties

calcBuilderVmap

protected calcBuilderVmap: Record<string, PlanVisitor<CalculationParams>>

Defined in: packages/core/src/optimizer/rules/merge-projections.ts:38

Per-language calculation-builder visitor instances.

---

db

protected db: DortDBAsFriend

Defined in: packages/core/src/optimizer/rules/merge-projections.ts:44

Internal database interface.

---

eqCheckersVmap

protected eqCheckersVmap: Record<string, EqualityChecker>

Defined in: packages/core/src/optimizer/rules/merge-projections.ts:40

Per-language equality-checker visitor instances.

---

operator

operator: typeof Projection = plan.Projection

Defined in: packages/core/src/optimizer/rules/merge-projections.ts:34

The operator this rule starts matching at.

Implementation of

PatternRule.operator

---

tdepsVmap

protected tdepsVmap: Record<string, TransitiveDependencies>

Defined in: packages/core/src/optimizer/rules/merge-projections.ts:36

Per-language transitive-dependency visitor instances.

Methods

calcToFnCall()

protected calcToFnCall(calc, args): FnCall

Defined in: packages/core/src/optimizer/rules/merge-projections.ts:118

Rebuilds a plan.FnCall from a calculation template with a new argument list, preserving aggregate metadata.

Parameters

Parameter	Type
calc	Calculation
args	OpOrId[]

Returns

FnCall

---

canMergeIntoOne()

protected canMergeIntoOne(a, b, projMap, calcInputDeps): [boolean, [Calculation | ASTIdentifier, ASTIdentifier][]]

Defined in: packages/core/src/optimizer/rules/merge-projections.ts:170

Parameters

Parameter	Type
a	Projection
b	Projection
projMap	ProjMap
calcInputDeps	Map<Calculation, IdSet>

Returns

[boolean, [Calculation | ASTIdentifier, ASTIdentifier][]]

[canMerge, attributes of b that are not filtered out by a]

---

getCalcInputDeps()

protected getCalcInputDeps(calc): IdSet

Defined in: packages/core/src/optimizer/rules/merge-projections.ts:218

Returns the union of transitive dependencies of all sub-operator arguments of calc.

Parameters

Parameter	Type
calc	Calculation

Returns

IdSet

---

getNewCalc()

protected getNewCalc(calc, projMap): Calculation

Defined in: packages/core/src/optimizer/rules/merge-projections.ts:138

Substitutes identifiers in calc using projMap and rebuilds the calculation.

Parameters

Parameter	Type
calc	Calculation
projMap	ProjMap

Returns

Calculation

---

match()

match(node): PatternRuleMatchResult<MergeProjectionsBindings>

Defined in: packages/core/src/optimizer/rules/merge-projections.ts:51

Matches the given plan operator against this rule.

Parameters

Parameter	Type	Description
node	Projection	The plan operator to match.

Returns

PatternRuleMatchResult<MergeProjectionsBindings>

Implementation of

PatternRule.match

---

mergeProjections()

protected mergeProjections(a, b): Projection

Defined in: packages/core/src/optimizer/rules/merge-projections.ts:76

Merges the inner projection b into the outer projection a, returning the surviving projection.

Parameters

Parameter	Type
a	Projection
b	Projection

Returns

Projection

---

transform()

transform(node, bindings): PlanOperator

Defined in: packages/core/src/optimizer/rules/merge-projections.ts:63

Transforms the given plan operator using the provided bindings.

Parameters

Parameter	Type	Description
node	Projection	The plan operator to transform.
bindings	MergeProjectionsBindings	The bindings to use for the transformation.

Returns

PlanOperator

Implementation of

PatternRule.transform