***CAUTION***

If you are installing over older version (below 0.50), you will need
to re-create your storages (both DB_File and Postgres).

                             *************


This is the README file for RDF::Core, a package for handling RDF data.

1. What is it RDF::Core?
2. Licensing
3. Warranty
4. Installation


1. What is RDF::Core?
========================================

RDF::Core is a pure perl implementation of RDF storage, parser, serializer 
and query. 

The storage functionality is basic - store, delete, query statements, where 
query means ask about existence or count or retrieve statements conforming 
given mask of (subject, predicate, object). Three storages are available - 
in memory, file (DB_File) and DBMS (PostgreSQL). 

The parser supports full RDF/XML syntax including aboutEach attribute (though 
it became obsolete). The serializer attempts to preserve anonymous nodes and 
to compact xml a bit grouping statements with common subject.

The query language is rather focused on resources than on statements. The 
typical pattern is me->neighbor->child->age to express neighbour's children's 
age, not (me,neighbour, him) && (him, child, it) && (it, age, value). 
It contains some shortcuts to express things, that are (possibly) expressed 
often, like object->rdf:type = someClass. Functions are another enhancement
of the language. They can be used instead of resource or property. Functions 
are implemented in a separated library, so that it's easy to create new or 
modify existing ones.

Original creator of RDF::Core is Ginger Alliance (www.gingerall.com).


2. Licensing
========================================

RDF::Core is an Open Source project released under the MPL (Mozilla Public 
License). Alternatively you may use RDF::Core under the GNU's GPL license.

Please, look at http://www.mozilla.org/MPL or
http://www.gnu.org/copyleft/gpl.html for further info.


3. Warranty
========================================

We offer NO WARRANTY for using RDF::Core in any conditions.


4. Installation
========================================

You need XML::Parser, version 2.3 or above and URI 1.03 or above to install 
RDF::Core. Optionally you need DBI (1.14) if you want Postgres data storage
and DB_File (1.72) for file data storage.


perl Makefile.PL
make test
make
make install (may require the root privileges)

DBMS storage installation (optional):

Create a PostgreSQL database. 
Load PL/pgSQL procedural language.
Change working directory to ./dbmodel/pgsql
Execute sql script in rdf-pgsql.sql

Of course, we're not able to test it on all Unix machines, so if you
meet any problem, feel free to contact us.



GA
rdf@gingerall.cz