On 12/10/2017 04:42 PM, Tom Lane wrote:
> Peter Geoghegan <pg@bowt.ie> writes:
>> On Sat, Dec 9, 2017 at 5:53 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>>> Overall I'm seeing about a 5% improvement in a "pgbench -S" scenario,
>>> although that number is a bit shaky since the run-to-run variation
>>> is a few percent anyway.
>
>> Is that with "-M prepared", too?
>
> No, I didn't use that.
>
FWIW I've done some measurements, and while there is a improvement, it's
far from 5%.
pgbench -S -c 1 -T 60
master patched
-----------------
18244 18534
18369 18587
18310 18479
18346 18515
18344 18557
pgbench -S -M prepared -c 1 -T 60
master patched
-----------------
35191 35231
35115 35555
35164 35686
35110 35724
35053 35762
So that's about 1.3% and 1.2% improvement. It seems fairly consistent,
but it might easily be due to different in layout of the binaries.
regards
--
Tomas Vondra http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services