On Thu, Aug 28, 2014 at 12:46 AM, Arthur Silva <arthur...@gmail.com> wrote: > > Em 26/08/2014 09:16, "Fujii Masao" <masao.fu...@gmail.com> escreveu: > > >> >> On Tue, Aug 19, 2014 at 6:37 PM, Rahila Syed <rahilasye...@gmail.com> >> wrote: >> > Hello, >> > Thank you for comments. >> > >> >>Could you tell me where the patch for "single block in one run" is? >> > Please find attached patch for single block compression in one run. >> >> Thanks! I ran the benchmark using pgbench and compared the results. >> I'd like to share the results. >> >> [RESULT] >> Amount of WAL generated during the benchmark. Unit is MB. >> >> Multiple Single >> off 202.0 201.5 >> on 6051.0 6053.0 >> pglz 3543.0 3567.0 >> lz4 3344.0 3485.0 >> snappy 3354.0 3449.5 >> >> Latency average during the benchmark. Unit is ms. >> >> Multiple Single >> off 19.1 19.0 >> on 55.3 57.3 >> pglz 45.0 45.9 >> lz4 44.2 44.7 >> snappy 43.4 43.3 >> >> These results show that FPW compression is really helpful for decreasing >> the WAL volume and improving the performance. >> >> The compression ratio by lz4 or snappy is better than that by pglz. But >> it's difficult to conclude which lz4 or snappy is best, according to these >> results. >> >> ISTM that compression-of-multiple-pages-at-a-time approach can compress >> WAL more than compression-of-single-... does. >> >> [HOW TO BENCHMARK] >> Create pgbench database with scall factor 1000. >> >> Change the data type of the column "filler" on each pgbench table >> from CHAR(n) to TEXT, and fill the data with the result of pgcrypto's >> gen_random_uuid() in order to avoid empty column, e.g., >> >> alter table pgbench_accounts alter column filler type text using >> gen_random_uuid()::text >> >> After creating the test database, run the pgbench as follows. The >> number of transactions executed during benchmark is almost same >> between each benchmark because -R option is used. >> >> pgbench -c 64 -j 64 -r -R 400 -T 900 -M prepared >> >> checkpoint_timeout is 5min, so it's expected that checkpoint was >> executed at least two times during the benchmark. >> >> Regards, >> >> -- >> Fujii Masao >> >> >> -- >> Sent via pgsql-hackers mailing list (email@example.com) >> To make changes to your subscription: >> http://www.postgresql.org/mailpref/pgsql-hackers > > It'd be interesting to check avg cpu usage as well.
Yep, but I forgot to collect those info... Regards, -- Fujii Masao -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers