Database size confusion

[Telemacus2]

I never had this issue before but there's something weird going on at my site:

My hosting provider keeps sending me warnings about the size of my forum's database. I have a forum with around 35.000 posts. Its size has always been around 300 MB. 

Recently, the size of the database has more than doubled (over 800MB, when the limit is 750.) At least that's what "Mysql Databases" says. But then, when I click on phpadmin, and I check the size of the tables on that database, it's still 3xxMB. Where are the other 4xx MB coming from?? 

The odd thing is that if I make some changes on my site, like changing the file system from data storage  method from file system to Mysql Database (or other simple operations, like installing a pluging and then deleting it again), mysql database in my CP, after a few minutes, displays the size of my database as 3xx again. But this only lasts for a few hours (between 24 and 48) and after that, it's doubled again, which makes no sense whatsoever.

Does anybody have any clues as to what could be going on?

[AndyF]

(unlikely) but you've not changed the storage type to use the database for attachments have you ? By this I mean storing them 'in' the database instead of the filesystem or on an external server etc

[bfarber]

1) Check for any "orig_" tables or anything like that. Older UTF8 conversion routines would make copies of every table, effectively doubling the size of the database. We have some checks in place in the recent releases that will alert you to this situation on the dashboard, but it's still worth double checking.

2) Look at the core_logs database table. In some cases this table can get large. If that's the case, you can truncate it, and then in the AdminCP look for "System Logs" in the live search, and on this page click the settings button to increase the prune time frame (e.g. from 90 days to 30 days, or something suitable for your site).

3) If you are storing attachments in the database, this will naturally balloon the size of your database. Don't do that.

If all else fails and you can't figure out where the reported size is coming from, contact your host and ask.