— tomauger.com

Depending on your web hosting situation, you may find yourself having to share a database among multiple WordPress installations, or perhaps other tables that have nothing to do with WordPress whatsoever. This is usually not a significant issue for your day-to-day because WordPress allows you to prefix your WP tables to be anything you like.

The challenge comes with backup and migration, particularly if you’re doing it manually via the shell command line.

Suppose you have a whole bunch of WP installations on a staging server awaiting review, all sharing a database. Now client XYZ has approved the site and it’s time to go live. We’ll take a mysqldump of just those tables and migrate that to the new server.

mysqldump takes, in addition to the authentication (-u and -p – and possibly -h) and database arguments, can take a list of tables to be included in the export. Once you supply even one table, any table not named is ignored. The problem is, particularly if you use plugins that create their own tables, the fixed list of tables can be a moving target. Can’t we select all tables with a given prefix?