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      SESSION LONGVARCHAR,
      ACCESSED TIMESTAMP,
      LOCKED INTEGER
  )

in particular the I<SESSION> column must be sufficiently large. I suggest
using something like up to 65535, for example I am using I<SHORT BLOB>
with MySQL.

The SESSION column must accept binary characters, in particular NUL bytes.
If it doesn't, you need to replace the I<Storable> package with I<FreezeThaw>.
L<Storable(3)>. L<FreezeThaw(3)>.

Ilya Ketris (ilya@gde.to) has pointed out, that these column names are
causing problems from time to time. He suggested to use queries like

  INSERT INTO $table ("ID", "SESSION", ...

instead. This is of course higly incompatible to other engines. To fix
that problem, I have added a subclass of I<HTML::EP::Session::DBI>,
called I<HTML::EP::Session::DBIq> (quoted). You use it by just replacing
the class name in the ep-session statement.


=head2 The Cookie subclass

This class is using Cookies, as introduced by Netscape 2. When using
Cookies for the session, you have to use a slightly different syntax:

  <ep-session class="HTML::EP::Session::Cookie" id="sessions"
              var=session id="$@cgi->id$" expires="+1h"
              domain="www.company.com" path="/"
              zlib=0 base64=0>

The attribute I<id> is the cookie's name. (Cookies are name/value
pairs.) The optional attributes I<expires>, I<domain> and I<path>
are referring to the respective attributes of CG::Cookie->new().
L<CGI::Cookie(3)>.

Cookies are unfortunately restricted to a certain size, about 4096
bytes. If your session is getting too large, you might try to reduce
the cookie size by using the Compress::Zlib and/or MIME::Base64
module. This is enabled by adding the parameters I<zlib=1> and/or
I<base64=1>.


=head2 The Dumper subclass

This is, in some sense, an unusual class for sessions: All users
are sharing a single session, unlike the DBI and Cookie subclasses,
which implement one session per user. I enjoy using the Dumper
subclass anyways, for example to implement site wide preferences.

What the class does is creating a file which holds a single
hash ref. This hash ref is created using the I<Data::Dumper>
package. L<Data::Dumper(3)>.

You create a Dumper session like this:

  <ep-session class="HTML::EP::Session::Dumper"
	      id="/var/tmp/my.session" var="prefs">

In other words, the session ID is just the name of the file.


=head1 MULTIPLE SESSION

When looking at the Cookie and Dumper subclass, the question arises:
Can I use multiple sessions within a single HTML page? Of course you
can!

However, there are a few drawbacks:

=over 8

=item 1.)

The variable $_ep_session_id$ always contains the ID of the
I<last> created session. After you have created the first
session, it will contains this sessions ID. If you create
another session, the variable will change to the new ID.

=item 2.)

You I<must> use the attributes B<var=something> and B<id=something>
with any call to I<ep-session>, I<ep-session-store>, I<ep-session-delete>
and I<ep-session-item>.

=back


=head1 AUTHOR AND COPYRIGHT

This module is

    Copyright (C) 1998    Jochen Wiedmann
                          Am Eisteich 9
                          72555 Metzingen
                          Germany

                          Phone: +49 7123 14887
                          Email: joe@ispsoft.de

All rights reserved.

You may distribute this module under the terms of either
the GNU General Public License or the Artistic License, as
specified in the Perl README file.


=head1 SEE ALSO

L<HTML::EP(3)>, L<Apache::Session(3)>, L<DBI(3)>, L<Storable(3)>,
L<FreezeThaw(3)>, L<CGI::Cookie(3)>

=cut