Frederick …. what about this solution below to using w3tc with hyperdb or multi-db? can i do this and still get to use your plugin for page caching and cdn…. what about the database caching should i leave that off?
……found this post
I should mention that there is an alternative to being able to use this plugin.
/w3-total-cache/lib/W3/Plugin/DbCache.php
change lines 126, 128 and 146. Rename db.php to db-cache.php
/w3-total-cache/lib/W3/Plugin/TotalCache.php
change line 2562. Rename db.php to db-cache.php
/w3-total-cache/wp-content/
Rename db.php to db-cache.php
When this is done, upload the files to your server, activate the plugin, and the db-cache.php file will be created and the plugin will be looking at this file instead of db.php.
The only downside is that you will need to do a manual upgrade when updates are loaded or it will over ride your changes and then over ride your current db.php file for multi-db.