Hi Melih, FYI -- The same testing was repeated but this time PG was configured to say synchronous_commit=on. Other factors and scripts were the same as before --- busy apply, 5 runs, 4 workers, 1000 inserts/tx, 100 empty tables, etc.
There are still more xlog records seen for the v26 patch, but now the v26 performance was better than HEAD. RESULTS (synchronous_commit=on) --------------------------------------------------- Xlog Counts HEAD postgres=# select avg(counttime) "avg", median(counttime) "median", min(counttime) "min", max(counttime) "max", logtype from test_head group by logtype; avg | median | min | max | logtype -----------------------+-----------------------+-----+------+----------- -----------------------+-----------------------+-----+------+----------- -----------------------+-----------------------+-----+------+----------- 1253.7509433962264151 | 1393.0000000000000000 | 1 | 2012 | FIND_DECODING_XLOG_RECORD_COUNT (1 row) HEAD+v26-0001 postgres=# select avg(counttime) "avg", median(counttime) "median", min(counttime) "min", max(counttime) "max", logtype from test_v26 group by logtype; avg | median | min | max | logtype -----------------------+-----------------------+-----+------+----------- -----------------------+-----------------------+-----+------+----------- -----------------------+-----------------------+-----+------+----------- 1278.4075471698113208 | 1423.5000000000000000 | 1 | 2015 | FIND_DECODING_XLOG_RECORD_COUNT (1 row) ~~~~~~ Performance HEAD [peter@localhost res_0809_vignesh_timing_sync_head]$ cat *.dat_SUB | grep RESULT | grep -v duration | awk '{print $3}' 4014.266 3892.089 4195.318 3571.862 4312.183 HEAD+v26-0001 [peter@localhost res_0809_vignesh_timing_sync_v260001]$ cat *.dat_SUB | grep RESULT | grep -v duration | awk '{print $3}' 3326.627 3213.028 3433.611 3299.803 3258.821 ------ Kind Regards, Peter Smith. Fujitsu Australia