Tom Lane wrote:
There's not much you can do to improve the performance of a restore already in progress. Next time you might want to think about kicking up maintenance_work_mem before you start it; that's about the only thing you can really do to speed up index builds.
I have found that increasing maintenance_work_mem can decrease index build speed on large tables: maintenance_work_mem 32768 262144 1048576 2097151 --------------------------------------------------------------- index 400M rows (min) 55 61 68 70 index 45M rows (min) 4.03 4.22 4.88 2.55 These timings were done on a machine with 8GB ram and postgresql 8.1.3 (from the RPMs on postgresql.org). Each time is an average of three runs; before each run, postgres was shut down and the filesystem with /var/lib/pgsql was remounted to clear the filesystem cache. I'm assuming that the times are increasing because there is less memory available for the filesystem cache. Similarly, I assume that the runs on the smaller table with maintenance_work_mem = 2097151 are faster because everything fits in that space. -- todd
