[eluser]mdvaldosta[/eluser]
Could you break that up into several databases? Honestly That'd be the best way to handle it. I once had a 4 gig database with 300k tables and it was a bitch to manage. If something broke, which happened about once a month, I'd end up having to do constant repairs that took several hours to complete and sometimes had to be ran a couple times. It was a nightmare. Splitting it off in a dozen databases fixed things up right as rain. No more crashes, no more long nights to fix db errors.
*edit - this wasn't on a dedicated db server, and it was several years ago when a quad core w/ 4 gigs of memory was pretty good. The issues were mostly related to memory useage and I'm sure with someone more experienced with tuning could have gotten a bit better. Nevertheless, it kept getting worse until I broke the db up. It's either that, or more power.
PSS - not a pissing contest, but I was also serving 40k uniques per day and 10mil 'post' messages. All on one server. Again, smaller dbs are better when that's possible. If you're going to be searching through all 300k records for one query - that'll be tough to do. But if it's a bunch of localized listings then you could probably get around to separating them by state or agent/company or whatever.
