On Wed, Dec 4, 2013 at 12:57 AM, Amit Kapila <amit.kapil...@gmail.com> wrote: >> As a quick side, we also repeated the same experiment on an EC2 instance >> with 16 CPU cores, and found that the scale out behavior became worse there. >> (We also tried increasing the shared_buffers to 30 GB. This change >> completely solved the scaling out problem on this instance type, but hurt >> our performance on the hi1.4xlarge instances.) > > Instead of 30GB, you can try with lesser value, but it should be close > to your data size.
The OS cache should have provided a similar function. In fact, larger shared buffers shouldn't have made a difference if the main I/O pattern are sequential scans, because they use a ring buffer. Can we have the explain analyze of those queries, postgres configuration, perhaps vmstat output during execution? -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
