=head1 NAME

Tangram::Driver::Pg - Orthogonal Object Persistence in PostgreSQL databases

=head1 SYNOPSIS

   use Tangram;
   use Tangram::Driver::Pg;

   $schema = Tangram::Driver::Pg->schema( $hashref );

   Tangram::Driver::Pg->deploy($schema, $dbh);

   $storage = Tangram::Driver::Pg->connect( $schema,
      $data_source, $username, $password );

   $storage->disconnect();

   Tangram::Driver::Pg->retreat($schema, $dbh);

=head1 DESCRIPTION

This is the entry point in the Pg-specific object-relational
persistence backend.

This module performs the following:

=head1 METHODS

This backend does not add any methods; for a description of
available methods, see L<Tangram::Relational>.

=head1 ERRATA

L<Tangram::Type::Dump::Storable> objects are first encoded with
L<MIME::Base64>, because Tangram does not currently have an easy
mechanism for calling C<DBI-E<gt>bind_param()> at the appropriate time
to flag the column as binary.

L<Tangram::Type::Dump::Perl> objects are stored as C<BYTEA> columns,
which as of L<DBD::Pg> 1.31, also do not get correctly escaped by the
DBD driver.  This also affects the (as-yet not fully functional)
L<Tangram::Type::Dump::YAML> back-end, which might put C<\> characters
into a YAML document.

It is recommended to use the C<storable> type with
L<Tangram::Type::Dump::Any> for this reason.

=cut