forum using incorrect database

[forcerr]

So i tried to upgrade my forum, made a mistake and now need to revert to a backed up database, i created a new db called username_forumtemp and restored the db, which was successful. I then went into my includes/config.php and changed the database from username_forum to username_forumtemp

But when i browse the forum i get errors relating to the old database, for example:

Database error in vBulletin 3.8.4:

Invalid SQL:
SELECT wordid, title FROM word WHERE title IN (....);

MySQL Error : Table 'username_forum.word' doesn't exist
Error Number : 1146
........

As you can see the error says username_forum.word doesn't exist.

I have changed the database name so why is it relating to the old db?

[forcerr]

I've went back to this today and the new database has kicked in.

Is there some sort of cache or store that saves queries etc that needs flushing if db name is changed?