Is That Possible to separate forum category database ?
 

now i have 3GB Size on my table " post "
and MySQL become crash and need repair every weekend
is that possible or anyone can recode the vbulletin for make different table of database for each category ?.

Example :

table : post_categorycar
table : post_categorylounge
table : post_categorymobile
table : post_categoryjokes

i hope you understand what i mean

If your server can't handle 3GB then there's another problem going on here. 3GB is not mind blowing high for the post table. Are you on shared hosting? VPS? Dedicated server?

Making a new table for each category is very wrong, vBulletin normalized the database for a reason. :)
And such modification is pretty much impossible, requires a lot of work.

The vb database is not normalized, you don't need to look beyond the user table to see that.

Yes I agree that they didn't normalize it to perfection, but I'm sure you know what I meant by that in this context.

Bit off-topic but a while ago I saw someone with a custom site that created a table for each customer with 30+ columns in each table. :D

because i have dream
possible make specific category of forum maintenance the database table
example : category JOKES have 2GB Size, and we close this this category, then we do the maintenance example analyze, repair etc. But other category still running smoothly.

Unfortunately it's not an option to make a table for each category. You'll have to upgrade your current server situation and/or tune/optimize your (My)SQL server.