NAME

Attean::Plan - Representation of SPARQL query plan operators

VERSION

This document describes Attean::Plan version 0.033

SYNOPSIS

  use v5.14;
  use Attean;

DESCRIPTION

This is a utility package that defines all the Attean query plan classes in the Attean::Plan namespace:

Attean::Plan::Quad
Evaluates a quad pattern against the model.
Attean::Plan::NestedLoopJoin
Evaluates a join (natural-, anti-, or left-) using a nested loop.
Attean::Plan::HashJoin
Evaluates a join (natural-, anti-, or left-) using a hash join.
Attean::Plan::Construct
Attean::Plan::Describe
Attean::Plan::EBVFilter
Filters results from a sub-plan based on the effective boolean value of a named variable binding.
Attean::Plan::Merge
Evaluates a set of sub-plans, returning the merged union of results, preserving ordering.
Attean::Plan::Union
Evaluates a set of sub-plans, returning the union of results.
Attean::Plan::Extend
Evaluates a sub-plan, and extends each result by evaluating a set of expressions, binding the produced values to new variables.
Attean::Plan::HashDistinct
Evaluates a sub-plan, and returns distinct results by checking a persistent hash of already-seen results.
Attean::Plan::Unique
Evaluates an already-ordered sub-plan, and returns distinct results by filtering out sequential duplicates.
Attean::Plan::Slice
Evaluates a sub-plan, and returns the results after optionally skipping some number of results ("offset") and limiting the total number of returned results ("limit").
Attean::Plan::Project
Evaluates a sub-plan and returns projected results by only keeping a fixed-set of variable bindings in each result.
Attean::Plan::OrderBy
Evaluates a sub-plan and returns the results after fully materializing and sorting is applied.
Attean::Plan::Service
Evaluates a SPARQL query against a remote endpoint.
Attean::Plan::Table
Returns a constant set of results.
Attean::Plan::Iterator
Returns a constant set of results.

Be aware that if the iterator being wrapped is not repeatable (consuming the Attean::API::RepeatableIterator role), then this plan may only be evaluated once.

A size estimate may be given if it is available. If the iterator is an Attean::ListIterator, the size of that iterator will be used.
Attean::Plan::ALPPath
Attean::Plan::Exists
Returns an iterator containing a single boolean term indicating whether any results were produced by evaluating the sub-plan.
Attean::Plan::Aggregate

BUGS

Please report any bugs or feature requests to through the GitHub web interface at <https://github.com/kasei/attean/issues>.

AUTHOR

Gregory Todd Williams "<gwilliams@cpan.org>"