On Thu, Nov 24, 2011 at 11:54 PM, Pavan Deolasee <pavan.deola...@gmail.com> wrote: > +1. These are independent patches and should be pursued like that. > BTW, I reviewed the pgxact-v2.patch and I have no objections to that > and it looks good to go in. Thanks Robert for making the necessary > changes and also running the benchmark tests.
I ran some write tests with master, pgxact-v2, and pgxact-v2+recentglobalxmin. shared_buffers = 8GB, maintenance_work_mem = 1GB, synchronous_commit = off, checkpoint_segments = 300, checkpoint_timeout = 15min, checkpoint_completion_target = 0.9, wal_writer_delay = 20ms. Seven five-minute runs at scale factor 100 for each configuration. Here's the executive summary: On the read-only test, recentglobalxmin.patch was only a win at the very highest concurrency I tested (80 clients); on the read-write test, it starts to show a benefit at much lower concurrencies (32 clients, certainly, perhaps even 8 clients, on unlogged tables). However, pgxact-v2.patch seems to be a win on both read and write tests and at any concurrency level, including the single-client case. == 1 client, unlogged tables == master: low 671.861618 median 677.324867 high 765.824313 (but the second highest was only 679.491822) pgxact-v2: low 663.901614 median 689.496716 high 696.812065 pgxact-v2+recentglobalxmin: low 665.554342 median 685.401979 high 688.832906 == 8 clients, unlogged tables == master: low 4722.011063 median 4758.201239 high 4920.130891 pgxact-v2: low 4684.759859 median 4840.081663 high 4979.036845 pgxact-v2+recentglobalxmin: low 4723.743270 median 4856.513904 high 4997.528399 == 32 clients, unlogged tables == master: low 10878.959662 median 10901.523672 high 10934.699151 pgxact-v2: low 17944.914228 median 18060.058996 high 19281.541088 pgxact-v2+recentglobalxmin: low 18894.860512 median 19637.190567 high 19817.089456 == 80 clients, unlogged tables == master: low 7872.934292 median 7897.811216 high 7909.410723 pgxact-v2: low 12032.684380 median 12397.316995 high 13279.998414 pgxact-v2+recentglobalxmin: low 16964.227483 median 17801.478747 high 18107.646170 == 1 client, permanent tables == master: low 625.502929 median 628.442284 high 677.451660 pgxact-v2: low 636.755782 median 640.083573 high 645.273888 pgxact-v2+recentglobalxmin: low 633.320412 median 636.898945 high 637.886099 == 8 clients, permanent tables == master: low 4497.012143 median 4624.844801 high 4849.233268 pgxact-v2: low 4561.914897 median 4625.443111 high 4776.095552 pgxact-v2+recentglobalxmin: low 4469.742226 median 4789.249847 high 4824.033794 == 32 clients, permanent tables == master: low 10468.362239 median 10511.425102 high 10531.069684 pgxact-v2: low 12821.732396 median 14500.067726 high 14546.538281 pgxact-v2+recentglobalxmin: low 14907.122746 median 15129.665408 high 15186.743199 == 80 clients, permanent tables == master: low 7601.067552 median 7612.898321 high 7631.487355 pgxact-v2: low 11712.895410 median 12004.807309 high 12512.078569 pgxact-v2+recentglobalxmin: low 15186.695057 median 15810.452158 high 16166.272699 I don't see much reason to wait around any further on the core patch (pgact-v2.patch) so I'll commit that now. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
