Quick answers to the questions that come up most. For the full walkthrough on anything here, follow the links at the end of each answer.

Getting started

What does DB Optimizer do?

It keeps your WordPress database lean and quick. You get a health score, bulk cleanup tools for clearing out junk like old revisions and expired transients, and tools to optimize your database tables. See Getting Started.

What do I need to run it?

WordPress 6.5 or higher and PHP 7.4 or higher.

Do I need Duplicator Pro to use it?

No. DB Optimizer works on its own. If you do happen to have Duplicator Pro, DB Optimizer adds a handy backup reminder on the Cleanup tab.

Cleanup and safety

Does cleanup delete anything for good?

Yes. Cleanup permanently deletes whatever you select, and there’s no undo inside the plugin. We really do recommend taking a backup with Duplicator Pro before you run it. See Back Up Before You Clean.

What kinds of data can I clear?

Nine: post revisions, auto-drafts, trashed posts, trashed comments, spam comments, expired transients, pingbacks, trackbacks, and embed (oEmbed) cache. See Cleaning Up Your Database.

Is it safe to clear all of these?

For most sites, yes. None of these are needed to display your site. The one thing to decide for yourself is whether you want to keep any trashed posts or comments. Recent items are protected automatically by your retention window.

What’s the retention window?

A “keep last X days” setting (7 days by default) that protects your newest data from cleanup. Anything newer than the window is never deleted. See Configuring the Retention Window.

I ran a cleanup but the count still shows items. Why?

On big sites, cleanup handles a set number of items per run so it stays quick. Just run it again to clear the rest.

Health score

What does the health score measure?

It’s a weighted blend of five things: table overhead (25%), expired transients (20%), post revisions (20%), autoload size (20%), and trash items (15%). The total runs from 0 to 100. See Understanding Your Database Health Score.

Why isn’t my score 100 after I cleaned everything?

A heavy autoload size is the usual reason. It’s normally controlled by other plugins rather than anything cleanup can fix, so it can hold the number down. The score also drifts naturally as your site makes new transients and revisions.

Tables

What’s the difference between Optimize and Repair?

Optimize wins back wasted space (overhead) and is routine upkeep you can run any time. Repair checks for and fixes actual table damage, which you only need when a table is genuinely broken. See Managing Database Tables.

Why does a table say “unsupported” when I repair it?

Modern WordPress runs on the InnoDB storage engine, and InnoDB doesn’t support the manual REPAIR command. It’s normal, not an error. InnoDB has its own built-in crash recovery.

Will DB Optimizer touch other databases or sites that share my database?

No. It only lists and works on tables that match your WordPress table prefix, so it’s safe on a shared database.