Maxing out DB Processes

I have read several threads here about people having similar problems and have taken the actions mentioned in them, but the problem persists. From one of those I learned about WP-Cache and installed that yesterday as well to try and fix it.

Every few hours my MSSQL hangs from too many processes running. Looking at them they are all around comments. This is crashing the server, now has my web hosting provider pissed and I can’t figure out what to do.

Lots of these:

| 15971153 | db6950 | 10.1.3.22:50189 | db6950_cc_wp | Query | 2058 | Waiting for table | DELETE FROM wp_comments WHERE DATE_SUB(‘2007-01-02 10:03:47’, INTERVAL 15 DAY) > comment_date_gmt AND comment_approved = ‘spam’ |
| 15971154 | db6950 | 10.1.3.13:42354 | db6950_cc_wp | Query | 2053 | Waiting for table | DELETE FROM wp_comments WHERE DATE_SUB(‘2007-01-02 10:03:52’, INTERVAL 15 DAY) > comment_date_gmt AND comment_approved = ‘spam’

Will a mass purge of comments help?

Is this a problem with too many spam comments? I’ve been manually going in and deleting them several times a day. Looked for a way to drop the Akismet setting to 1 day instead of 15 but didn’t find it.

I’m really stuck here. I love WP and want to continue using it, but I can’t seem to get around.

ANY help would be hugely thankful