readme.sqlite

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SQLITE3 DATABASE DRIVER FOR BOGOFILTER
======================================

$Id: README.sqlite,v 1.6 2005/12/26 02:01:23 m-a Exp $

This document only applies if you want to use bogofilter with SQLite3
databases.

1. Overview -----------------------------------------------------------

Bogofilter 0.93.3 and newer can use SQLite 3.2.6 and newer to store
their tokens. SQLite is a database that handles a large SQL subset and
stores all tables in one permanent file, and the journal for changes in
one temporary file that gets automatically removed when no longer
needed. SQLite3 ships with a command-line client for the shell, named
sqlite3.

2. Prerequisites ------------------------------------------------------

2.1 Compatibility - supported SQLite versions

At this time, only SQLite 3.2.6 and newer are supported. Older versions
back to 3.0.8 may work, but you are advised to carefully review the
sqlite3 ChangeLog, because there have been several important bug fixes
between 3.0.8 and 3.2.8. Bogofilter prints a warning (but continues to
run) when used with SQLite versions older than 3.2.6.

2.2 Installation

To use bogofilter with the SQLite3 back-end driver, you must install
SQLite 3.2.6 or newer before configuring bogofilter. You can download
SQLite 3 and find installation instructions for SQLite 3 at
<http://sqlite.org/>, the SQLite installation is pretty straightforward.

After that, you can configure bogofilter, add --with-database=sqlite
to the ./configure command.

3. Use ----------------------------------------------------------------

3.1 Care and feeding

SQLite is pretty self-maintaining.  After larger maintenance operations
to remove older tokens you may want to run this command:

    sqlite3 ~/.bogofilter/wordlist.db 'VACUUM;'

to remove unused pages from the database file and reduce the file size.

A. Miscellaneous ------------------------------------------------------

A.1 Why does bogofilter use BLOB for both columns?

bogofilter has traditionally managed its own data structure inside key
and value, BLOB allows the verbatim retrieval of such data without
stumbling across embedded NUL characters.