Jim Nasby wrote: > On Feb 19, 2007, at 1:19 PM, Jeff Davis wrote: >> You told PostgreSQL that you have 900MB available for >> maintenance_work_mem, but your OS is denying the request. Try *lowering* >> that setting to something that your OS will allow. That seems like an >> awfully high setting to me. > > 900MB isn't that unreasonable if you're building indexes on a restore or > something similar. I have run into issues when trying to set it much > over 1G, though... on various OSes and platforms. versions before 8.2 have some issues(mostly reporting bogus errors) with very large settings for maintenance_work_mem. 8.2 and up are behaving more sanely but I don't think they can actually make anything better with values in the GB range. Have you actually measured a performance improvment going beyond 250-350MB(that seemed about to be the sweet spot last I tested) or so for index creation and friends ? Stefan
