# Redland RDF Application Framework - Perl RDF::Redland::Storage Class

## NAME

RDF::Redland::Storage - Redland RDF Storage Class

## SYNOPSIS

      use RDF::Redland;
      my $storage=new RDF::Redland::Storage("hashes", "test", "new='yes',hash-type='memory'");
      ...

## DESCRIPTION

Create objects for storing RDF::Redland::Model objects either persistently or in memory.

## CONSTRUCTORS

new STORAGE_NAME [NAME [OPTIONS_STRING]]

  Create a new RDF::Redland::Storage object for the storage factory named STORAGE_NAME with storage named NAME and storage options OPTIONS_STRING which are specific to the storage factory type.

  The storage options may be given either as a Perl hash or as a string. The string form are formatted in the form key1='value1',key2='value2' and the single quotes are required. The Perl hash form follows normal Perl conventions, and the boolean options use normal Perl concepts of truth.

  Currently defined storage options:

  new='yes'

    Create a new storage erasing any existing one (boolean, default).

  write='yes'

    Provide write access to store (boolean, default) otherwise is read only.

  dir='DIR'

    Work in DIR directory when creating files.

  mode='MODE'

    File creation mode, default is (octal) 0644 Takes decimal (123), hex (0x123) or octal (0123).

  contexts='yes'

    Enable statement contexts. Each statement can be stored with an optional context Node and the context retrieved after queries. Boolean.

  hash-type='TYPE' (hashes storage only)

    Use the TYPE hash-type for hashes storage. Current defined types are 'memory' and 'bdb' but is dependent on the hash factories available.

  index-predicates='yes' (hashes storage only)

    Enable indexing from predicates to (subject,object) which can in particular be useful for rdf:type relations. Boolean.

  bulk='no' (mysql storage only)

    Whether model/storage method add_statements should be optimized, until a model/storage sync operation. Boolean.

  merge='no' (mysql storage only)

    Whether to maintain a table with merged models. Boolean.

  Example, string form:

        $storage=new RDF::Redland::Storage("hashes", "test",
                                  "new='yes',hash-type='bdb',dir='.'");

  Example, Perl hash form:

        $storage=new RDF::Redland::Storage("hashes", "test",
                                  {new=>1,hash-type=>'bdb',dir=>'.'});

  Creates a new storage of the hashes type (indexed hashes) named test (these will be file names or URIs if the storage is persistent) and with options new='yes',hash-type='bdb',dir='.' so a new storage is created with BerkeleyDB (BDB) key:value hashes i.e. persistent and in the current directory.

  Example, Perl hash form:

        $storage=new RDF::Redland::Storage("mysql", "test", {host=>'localhost',database=>'testdb',user=>'testuser',new=>0,password=>'',contexts=>1});

  Uses an existing storage of the mysql type, named test on localhost with database name testdb using a user testuser and no password. Contexts are enabled.

new_from_storage STORAGE

  Create a new RDF::Redland::Storage object from RDF::Redland::Storage STORAGE (copy constructor). The new storage may have a new name chosen by the storage factory.

## SEE ALSO

the RDF::Redland::Model manpage

## AUTHOR

Dave Beckett - http://www.dajobe.org/

(C) Copyright 2000-2011 Dave Beckett, (C) Copyright 2000-2005 University of Bristol