---
name: "AtteanX::Store::LDF"
section: "3pm"
platform: "linux"
package: "libatteanx-store-ldf-perl"
version: "0.04-3"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/AtteanX::Store::LDF"
---

# AtteanX::Store::LDF(3pm)

Linked Data Fragment RDF store

## NAME

AtteanX::Store::LDF - Linked Data Fragment RDF store

## SYNOPSIS

```
    use v5.14;
    use Attean;
    use Attean::RDF qw(iri blank literal);
    use AtteanX::Store::LDF;
    my $uri   = 'http://fragments.dbpedia.org/2014/en';
    my $store = Attean->get_store('LDF')->new(start_url => $uri);
    my $iter = $store->get_triples(undef,undef,literal("Albert Einstein"));
    while (my $triple = $iter->next) {
     say $triple->subject->ntriples_string .
       " " .
       $triple->predicate->ntriples_string .
       " " .
       $triple->object->ntriples_string  .
       " .";
    }
```

## DESCRIPTION

AtteanX::Store::LDF provides a triple-store connected to a Linked Data Fragment server. For more information on Triple Pattern Fragments consult \<http://linkeddatafragments.org/\>

## METHODS

Beyond the methods documented below, this class inherits methods from the Attean::API::TripleStore class.

- new( start\_url =\> $start\_url )

  Returns a new LDF-backed storage object. The required `"start_url"` argument is a URL pointing at any Linked Data Fragment. The attribure will be coerced, so it can be a string, a URI object, etc.

- count\_triples\_estimate( $subject, $predicate, $object )

  Return the count of triples matching the specified subject, predicate and  objects.

- get\_triples( $subject, $predicate, $object)

  Returns a stream object of all statements matching the specified subject, predicate and objects. Any of the arguments may be undef to match any value.

- cost\_for\_plan($plan)

  Returns an cost estimation for a single LDF triple based on estimates. The cost will be in the interval 10-1000 if the supplied argument is a AtteanX::Plan::LDF::Triple, undef otherwise.

- plans\_for\_algebra($algebra)

  Returns an empty plan since access\_plans generates the needed plans.

## SEE ALSO

Attean , Attean::API::TripleStore

## BUGS

Please report any bugs or feature requests to through the GitHub web interface at \<https://github.com/phochste/AtteanX-Store-LDF\>.

## AUTHOR

Patrick Hochstenbach  `"<patrick.hochstenbach@ugent.be>"` Kjetil Kjernsmo \<kjetilk@cpan.org\>.

## COPYRIGHT

This software is copyright (c) 2015 by Patrick Hochstenbach. This software is copyright (c) 2016 by Patrick Hochstenbach and Kjetil Kjernsmo. This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.