On Thursday, October 04, 2012 8:03 PM Heikki Linnakangas wrote: On Wednesday, October 03, 2012 9:33 PM Amit Kapila wrote: On Friday, September 28, 2012 7:03 PM Amit Kapila wrote: > > On Thursday, September 27, 2012 6:39 PM Amit Kapila wrote: > > > On Thursday, September 27, 2012 4:12 PM Heikki Linnakangas wrote: > > > On 25.09.2012 18:27, Amit Kapila wrote: > > > > If you feel it is must to do the comparison, we can do it in same > > way > > > > as we identify for HOT? > > > > > > > Now I shall do the various tests for following and post it here: > > a. Attached Patch in the mode where it takes advantage of history > > tuple b. By changing the logic for modified column calculation to use > > calculation for memcmp() > >
> 1. Please find the results (pgbench_test.htm) for point -2 where there is > one fixed column updation (last few bytes are random) and second column > updation is 32 byte random string. The results for 50, 100 are still going > on others are attached with this mail. Please find the readings of LZ patch along with Xlog-Scale patch. The comparison is between for Update operations base code + Xlog Scale Patch base code + Xlog Scale Patch + Update WAL Optimization (LZ compression) The readings have been taken based on below data. pgbench_xlog_scale_50 - a. Updated Record size 50, Total Record size 1800 b. Threads 8, 1 ,2 c. Synchronous_commit - off, on pgbench_xlog_scale_250 - a. Updated Record size 250, Total Record size 1800 b. Threads 8, 1 ,2 c. Synchronous_commit - off, on pgbench_xlog_scale_500- a. Updated Record size 500, Total Record size 1800 b. Threads 8, 1 ,2 c. Synchronous_commit - off, on Observations -------------- a. There is still a good performance improvement even if we do Update WAL optimization on top of Xlog Sclaing Patch. b. There is a slight performance dip for 1 thread (only in Sync mode = off) with Update WAL optimization (LZ compression) but for 2 threads there is a performance increase. With Regards, Amit Kapila. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers