Dual databases

[Martz]

My co-developer and I are working on using 2 mySQL databases for vB - to lighten the load on attachments. We've run into some teething problems replicating the $DB_site-> function ($DB_attach->)

Is it possible to use 2 databases at once? Is it known to cause problems? Should we close the connections to 1 db before quering the other?

Thanks for any help.

[Admin]

If you are using the same user/pass for the two databases, it's really simple actually.

All you need to do, is first move the attachment table from one db to the other.
Then, find all places where you have SELECT [...] FROM attachment, and change that to newDBname.attachment (also do that for JOINs with the attachment table).

The places I can currently think about are:
showthread.php (where you select the posts there should be a reference there to that table)
attachment.php (duh)
functions.php (acceptupload() is the function that actually adds the files to the database...)

Good luck.

[Admin]

(And if you don't have the same user/pass for the databases, first yell at your host for being dense, then... I don't know. )

[Martz]

The problem is it's not on the same server. 2 different databases on 2 different servers. So if i'm not mistaken your solution would only help if the 2 db's are on the same server?

Thanks

[Admin]

Yup... heh I was wondering how it would help to have two databases on the same servers rather than one.

In that case, just copy the code from global.php that starts $DB_site, and duplicate it using $DB_attach... then use that new object when selecting stuff from attachment table, although you will have problems with JOINs.

[Martz]

Yeah - we're looking at re-writting these queries now, which I am guessing will make it less effcient - but we'll see when we get there.