On Mon, 2008-09-22 at 04:57 -0400, Greg Smith wrote: > -As Greg Stark suggested, the larger the spindle count the larger the > speedup, and the larger the prefetch size that might make sense. His > suggestion to model the user GUC as "effective_spindle_count" looks like a > good one. The sequential scan fadvise implementation patch submitted uses > the earlier preread_pages name for that parameter, which I agree seems > less friendly.
Good news about the testing. I'd prefer to set this as a tablespace level storage parameter. Since that is where it would need to live when we have multiple tablespaces. Specifically as a storage parameter, so we have same syntax for table-level and tablespace-level storage parameters. That would also allow us to have tablespace-level defaults for table-level settings. prefetch_... is a much better name since its an existing industry term. I'm not in favour of introducing the concept of spindles, since I can almost hear the questions about ramdisks and memory-based storage. Plus I don't ever want to discover that the best setting for effective_spindles is 7 (or 5) when I have 6 disks because of some technology shift or postgres behaviour change in the future. -- Simon Riggs www.2ndQuadrant.com PostgreSQL Training, Services and Support -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
