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.