---
name: "Lire::DerivedSchema"
section: "3pm"
platform: "linux"
package: "lire"
version: "2.1.1-8"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/Lire::DerivedSchema"
---

# Lire::DerivedSchema(3pm)

Defines a schema for which the records are derived from another schema

## NAME

Lire::DerivedSchema - Defines a schema for which the records are derived from another schema

## SYNOPSIS

```
  my $schema = Lire::DlfSchema::load_schema( 'www-user_session' );
  my $fields = $schema->fields();
```

## DESCRIPTION

A Lire::DerivedSchema defines a schema for which the records are computed by an analyser using the records of a base schema. An example of a derived schema is the www-user\_session schema which computes session information from the records in the www schema.

### base()

Returns the Lire::DlfSchema object from which this schema's records are derived.

### can\_join\_schema( $schema )

Returns true if `$schema` can be joined with this schema. For a DerivedSchema, this will be true only when `$schema` is an ExtendedSchema of this schema or this schema's base. It is also possible to join the DerivedSchema with its base.

## AUTHOR

Francis J. Lacoste \<flacoste@logreport.org\>

## VERSION

`$Id:` DerivedSchema.pm,v 1.19 2006/07/23 13:16:28 vanbaal Exp $

## COPYRIGHT

Copyright (C) 2001, 2004 Stichting LogReport Foundation LogReport@LogReport.org

This file is part of Lire.

Lire is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program (see COPYING); if not, check with http://www.gnu.org/copyleft/gpl.html.