> We are running some performance tests in which we are attempting to > insert about 100,000,000 rows in a database at a sustained rate. About > 50M rows in, our performance drops dramatically. > > This test is with data that we believe to be close to what we will > encounter in production. However in tests with purely generated, > sequential data, we did not notice this slowdown. I'm trying to figure > out what patterns in the "real" data may be causing us problems. > > I have log,data and indexes on separate LUNs on an EMC SAN. Prior to > slowdown, each partition is writing at a consistent rate. Index > partition is reading at a much lower rate. At the time of slowdown, > index partition read rate increases, all write rates decrease. CPU > utilization drops.
I'm doing some test-inserts (albeit with much fewer records) into 8.0.4 (on FreeBSD 6.0 RC1) and the import-time decreased three-fold when I increased the below mentioned values: shared_buffers = 8192 commit_delay = 100000 commit_siblings = 1000 When I increased shared_buffers the kernel needed minor tweaking. regards Claus ---------------------------(end of broadcast)--------------------------- TIP 4: Have you searched our list archives? http://archives.postgresql.org