large database throwing "mysql has gone away" errors

Hi. I’m working w/a client whose site has been up since 2011. She blogs & also has a BBPress forum. The difficulty is that the database has grown to over a gig & a half, w/the wp_postmeta table comprising the majority of that, weighing in at a hefty 1gb. She’s running the latest versions of both WordPress & BBPress.

As you might well imagine, she’s getting a lot of ‘mysql has gone away” type errors. Because the site deals w/a sport, which is somewhat seasonal, my thought was to perhaps separate the site in such a way that only this year’s content was displayed, while displaying archives on a separate subdomain. BBPress, however, refused to cooperate in that regard, giving me the “o, bother, no topics were found here” message when clicking on any of the forums, though the number of topics was listed & seemed to be right.

I’m going to cross-post this to both the WordPress & BBPress forums (though my luck in the latter has not been exactly stellar, because I have 2 questions, each of which pertains more to the 1 forum than the other. My first question is does anyone have any suggestions about methods that might be used to significantly decrease the database size? For those over at BBPress, is there any way to export content for a specific date range & have it display correctly?

Thanks for any assistance. I could really use a little at this juncture.