Class AggregateStageBuilder

An AggregateStageBuilder handles the evaluation of Aggregations operations, GROUP BY and HAVING clauses in SPARQL queries.

see: https://www.w3.org/TR/sparql11-query/#aggregates
author: Thomas Minier

Hierarchy

StageBuilder
- AggregateStageBuilder

Index

Constructors

constructor

Properties

Accessors

Methods

Constructors

constructor

new AggregateStageBuilder(_dataset: Dataset): AggregateStageBuilder

Inherited from StageBuilder.constructor
- Defined in src/engine/stages/stage-builder.ts:39
Parameters
- _dataset: Dataset
Returns AggregateStageBuilder

Properties

Protected _builder

_builder: PlanBuilder | null = null

Protected _dataset

_dataset: Dataset

Accessors

builder

get builder(): PlanBuilder | null
set builder(builder: PlanBuilder | null): void

Inherited from StageBuilder.builder
- Defined in src/engine/stages/stage-builder.ts:43
Returns PlanBuilder | null
Inherited from StageBuilder.builder
- Defined in src/engine/stages/stage-builder.ts:47
Parameters
- builder: PlanBuilder | null
Returns void

dataset

get dataset(): Dataset
set dataset(dataset: Dataset): void

Inherited from StageBuilder.dataset
- Defined in src/engine/stages/stage-builder.ts:51
Returns Dataset
Inherited from StageBuilder.dataset
- Defined in src/engine/stages/stage-builder.ts:55
Parameters
- dataset: Dataset
Returns void

Methods

_executeGroupBy

_executeGroupBy(source: PipelineStage<Bindings>, groupby: Aggregation[], context: ExecutionContext, customFunctions?: CustomFunctions): PipelineStage<Bindings>

- Defined in src/engine/stages/aggregate-stage-builder.ts:71
Build a PipelineStage for the evaluation of a GROUP BY clause

Parameters
- source: PipelineStage<Bindings>
  
  Input PipelineStage
- groupby: Aggregation[]
  
  GROUP BY clause
- context: ExecutionContext
- Optional customFunctions: CustomFunctions
Returns PipelineStage<Bindings>

A PipelineStage which evaluate a GROUP BY clause

_executeHaving

_executeHaving(source: PipelineStage<Bindings>, having: Expression[], context: ExecutionContext, customFunctions?: CustomFunctions): PipelineStage<Bindings>

- Defined in src/engine/stages/aggregate-stage-builder.ts:93
Build a PipelineStage for the evaluation of a HAVING clause

Parameters
- source: PipelineStage<Bindings>
  
  Input PipelineStage
- having: Expression[]
  
  HAVING clause
- context: ExecutionContext
- Optional customFunctions: CustomFunctions
Returns PipelineStage<Bindings>

A PipelineStage which evaluate a HAVING clause

execute

execute(source: PipelineStage<Bindings>, query: RootNode, context: ExecutionContext, customFunctions?: CustomFunctions): PipelineStage<Bindings>

Overrides StageBuilder.execute
- Defined in src/engine/stages/aggregate-stage-builder.ts:52
Build a PipelineStage for the evaluation of SPARQL aggregations

Parameters
- source: PipelineStage<Bindings>
  
  Input PipelineStage
- query: RootNode
  
  Parsed SPARQL query (logical execution plan)
- context: ExecutionContext
- Optional customFunctions: CustomFunctions
Returns PipelineStage<Bindings>

A PipelineStage which evaluate SPARQL aggregations

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