Arefly

Post revisions are backups of articles editors are writing and forgot to hit save. They are also article versions stored in the WP database, as a way to see how the post’s content evolved.
While they are important for this later reason, sometimes WordPress creates post revisions with minimal changes to the post content. These are “redundant” post revisions and they do nothing more but slow down page loading time and bulk up the database with useless content.
This WordPress plugin can help webmasters delete these kind of redundant posts.
中文介紹請看<a href="http://www.arefly.com/delete-post-revision/" rel="nofollow ugc">這裏</a>
<h4>Translators</h4>
<ul>
<li>Chinese, Simplified (zh_CN) – <a href="http://www.arefly.com/" rel="nofollow ugc">Arefly</a></li>
<li>Chinese, Traditional (zh_TW) – <a href="http://www.arefly.com" rel="nofollow ugc">Arefly</a></li>
<li>English (en_US) – <a href="http://www.arefly.com" rel="nofollow ugc">Arefly</a></li>
</ul>
If you have created your own language pack, or have an update of an existing one, you can send <a href="https://codex.wordpress.org/Translating_WordPress" rel="nofollow ugc">gettext PO and MO files</a> to <a href="http://www.arefly.com/about/" rel="nofollow ugc">Arefly</a> so that I can bundle it into Delete Post Revision. You can download the latest <a href="https://plugins.svn.wordpress.org/delete-post-revision/trunk/lang/delete-post-revision.pot" rel="nofollow ugc">POT file</a>.

Delete Post Revision

Help you clean out redundant & repetitive post revisions and thin out the database.

pranacoder

WordPress stores a lot of excess information in your DB (like post revisions, auto drafts, spam and trashed comments, transient site options, etc.). 
Of course there’s a reason for that and some of this data is needed once in a while, but most of it is not critical. It just sits there taking up space and never being used. 
Over the time as your site grows the volume of this unused data grows with it making your database unreasonably huge thus effecting the site’s overall performance.
Using WUCO you can easily and safely clean up your database from those useless entries. With a single click you can remove revisions, drafts, auto drafts, orphaned post and comment meta, transient data and much more. You can also schedule the cleanups for later and they will be run automatically keeping your WordPress site clean and shiny.
And as all the best things in life WUCO is and always will be absolutely free.

WUCO – WP Ultimate Cleanup & Optimization

WUCO aka WP Ultimate Cleanup & Optimization, a free easy to use yet effective plugin designed to help you keep your MySQL database clean.

Delete Post Revision vs WUCO – WP Ultimate Cleanup & Optimization