Database Prefix

The database prefix is a short string Joomla adds before each table in the database during installation. This lets you run multiple Joomla installations in a single database and makes it harder to automatically exploit security vulnerabilities.

  • Function and Purpose

    During installation Joomla automatically generates a random prefix that is prepended to all table names (e.g. j5x_). This prevents collisions with other installations and makes it harder for attackers to guess table names.

    Customization and Use

    • Multiple installations: Different prefixes let you run multiple Joomla instances in one database.
    • Manual change: You can change the prefix afterward, but it requires experience with databases and tools like phpMyAdmin.
    • Security: Random prefixes make SQL injection attacks more difficult.

    Important Notes

    • Backups: Always create a backup before manually changing the prefix.
    • Configuration file: The prefix is defined in configuration.php and must match the table names.
    • One-time per installation: Usually there’s no need to change the prefix after installation.
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    Need help with database management or migration? We’re happy to advise you.

    See also