I thought the sky almost fell down just then when I went to my gallery2 installation (/gallery) and saw that it had a database error. “Noooo!!! I’ll have to spend hours reinstalling and uploading again!” The error in question was
An error has occurred while interacting with the database.
If you get this error, don’t panic. For me, it turned out that one of the database tables was corrupted and needed repairing. Log in to phpMyAdmin or to the mysql console and check whether any of the tables are listed as corrupt. In my case, it turned out to be g2_CacheMap.
I snooped around some forums, and in the threads that had responses (a lot of forums have questions left unanswered unfortunately), it seems like the blame lies with your host having a bad mysql setup or bad hard drives that corrupt at random. Shame on you, Bluehost.