Since updating to WordPress 3.5 I’ve had my updates of pages and posts become excessively slow. I’ve been timing them and they take 40-80 seconds to update.
I’ve spent the last 2 hours reading and trying everything I can find in the WordPress.org forums yet nothing works.
I use maxcdn and CloudFlare for the frontside but the backside is unbearable.
I am on a MU install using 3.5.2 and I have disabled and tested each plugin. Seems to be a WordPress issue and I’m looking for a workaround.
I’m on dual core VPS with 3GB of ram.
There’s a plugin called Debug Bar which you can find at http://wordpress.org/plugins/debug-bar/ Don’t leave this enabled in production! But it will tattle on slow MySQL queries.
You might also wish to try using WP Clean Up. http://wordpress.org/plugins/wp-clean-up/ This flushes out stale entries in your database, and does a little bit of table reorg/optimization.
I had the same thing today. It turned out that WP Maintenance Mode plugin slowed down my website. After I deactivated the plugin, all was good again.
Maybe it helps someone.
Nine years on, further investigation of this slowdown on post and page updates shows that sites with lots of users are inefficient. It’s the dropdown list of potential authors that causes the problem. The fix is to stop using MySQL queries that look like this
in favor of queries that look like this
Rigging that up is a little tricky, but I’ve made a free GPL plugin for the purpose. Index WP Users For Speed.