Josh, On 9/29/05 9:54 AM, "Josh Berkus" <josh@agliodbs.com> wrote:
> Following an index creation, we see that 95% of the time required is the > external sort, which averages 2mb/s. This is with seperate drives for > the WAL, the pg_tmp, the table and the index. I've confirmed that > increasing work_mem beyond a small minimum (around 128mb) had no benefit > on the overall index creation speed. Yuuuup! That about sums it up - regardless of taking 1 or 2 passes through the heap being sorted, 1.5 - 2 MB/s is the wrong number. This is not necessarily an algorithmic problem, but is a optimization problem with Postgres that must be fixed before it can be competitive. We read/write to/from disk at 240MB/s and so 2 passes would run at a net rate of 120MB/s through the sort set if it were that efficient. Anyone interested in tackling the real performance issue? (flame bait, but for a worthy cause :-) - Luke ---------------------------(end of broadcast)--------------------------- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly