Class: IndexScans

Defined in: packages/core/src/optimizer/rules/index-scans.ts:41

Finds selections that can be satisfied by an index scan and replaces them with an index scan operator.

Implements

• PatternRule<Selection, IndexScansBindings>

Constructors

Constructor

new IndexScans(db): IndexScans

Defined in: packages/core/src/optimizer/rules/index-scans.ts:47

Parameters

Parameter	Type	Description
db	DortDBAsFriend	Internal database interface.

Returns

IndexScans

Properties

calcBuilders

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

Defined in: packages/core/src/optimizer/rules/index-scans.ts:43

Per-language calculation-builder visitor instances.

---

db

protected db: DortDBAsFriend

Defined in: packages/core/src/optimizer/rules/index-scans.ts:49

Internal database interface.

---

eqCheckers

protected eqCheckers: Record<string, EqualityChecker>

Defined in: packages/core/src/optimizer/rules/index-scans.ts:45

Per-language equality-checker visitor instances.

---

operator

operator: typeof Selection = Selection

Defined in: packages/core/src/optimizer/rules/index-scans.ts:219

The operator this rule starts matching at.

Implementation of

PatternRule.operator

Methods

getExprCandidates()

protected getExprCandidates(selections): IndexMatchInput & object[]

Defined in: packages/core/src/optimizer/rules/index-scans.ts:172

Extracts IndexMatchInput candidates from the given selections, tagged with their selection-array index.

Parameters

Parameter	Type
selections	Selection[]

Returns

---

match()

match(node): PatternRuleMatchResult<IndexScansBindings>

Defined in: packages/core/src/optimizer/rules/index-scans.ts:55

Matches the given plan operator against this rule.

Parameters

Parameter	Type	Description
node	Selection	The plan operator to match.

Returns

PatternRuleMatchResult<IndexScansBindings>

Implementation of

PatternRule.match

---

matchIndex()

protected matchIndex(index, candidates, renameMap): object

Defined in: packages/core/src/optimizer/rules/index-scans.ts:114

Tests whether index can satisfy any of the candidates; returns the surviving candidates and an accessor, or null.

Parameters

Parameter	Type
index	Index
candidates	IndexMatchInput & object[]
renameMap	RenameMap

Returns

accessor

accessor: Calculation

Calculation that invokes the index to retrieve matching records.

candidates

candidates: IndexMatchInput & object[]

Filtered candidates that participate in the matched index expression.

---

transform()

transform(node, bindings): PlanOperator

Defined in: packages/core/src/optimizer/rules/index-scans.ts:187

Transforms the given plan operator using the provided bindings.

Parameters

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

Returns

PlanOperator

Implementation of

PatternRule.transform