Hi Folk, I am trying to investigate some performance issues which we have with postgres (a different topic by itself) and tried postgres.9.4beta2, with a hope that it perform better. Turned out that 9.4 is 2x slower than 9.3.5 on the same hardware. Some technical details: Host: rhel 6.5 2.6.32-431.23.3.el6.x86_64 256 GB RAM, 40 cores, Intel(R) Xeon(R) CPU E5-2660 v2 @ 2.20GHz 2x160GB PCIe SSD DELL_P320h-MTFDGAL175SAH ( on one 9.3, on an other one 9.4 ) postgres tweaks: default_statistics_target = 100 wal_writer_delay = 10s vacuum_cost_delay = 50 synchronous_commit = off maintenance_work_mem = 2GB checkpoint_completion_target = 0.9 effective_cache_size = 94GB work_mem = 402MB wal_buffers = 16MB checkpoint_segments = 64 shared_buffers = 8GB max_connections = 100 random_page_cost = 1.5 # other goodies log_line_prefix = '%m <%d %u %r> %%' log_temp_files = 0 log_min_duration_statement = 5 in both cases databases are fresh - no data. Here is a results with pgbench. 9.3.5: # /usr/pgsql-9.3/bin/pgbench -r -j 1 -c 1 -T 60 starting vacuum...end. transaction type: TPC-B (sort of) scaling factor: 1 query mode: simple number of clients: 1 number of threads: 1 duration: 60 s number of transactions actually processed: 96361 tps = 1605.972262 (including connections establishing) tps = 1606.064501 (excluding connections establishing) statement latencies in milliseconds: 0.001391 \set nbranches 1 * :scale 0.000473 \set ntellers 10 * :scale 0.000430 \set naccounts 100000 * :scale 0.000533 \setrandom aid 1 :naccounts 0.000393 \setrandom bid 1 :nbranches 0.000468 \setrandom tid 1 :ntellers 0.000447 \setrandom delta -5000 5000 0.025161 BEGIN; 0.131317 UPDATE pgbench_accounts SET abalance = abalance + :delta WHERE aid = :aid; 0.100211 SELECT abalance FROM pgbench_accounts WHERE aid = :aid; 0.117406 UPDATE pgbench_tellers SET tbalance = tbalance + :delta WHERE tid = :tid; 0.114332 UPDATE pgbench_branches SET bbalance = bbalance + :delta WHERE bid = :bid; 0.086660 INSERT INTO pgbench_history (tid, bid, aid, delta, mtime) VALUES (:tid, :bid, :aid, :delta, CURRENT_TIMESTAMP); 0.035940 END; 9.4beta2: # /usr/pgsql-9.3/bin/pgbench -r -j 1 -c 1 -T 60 starting vacuum...end. transaction type: TPC-B (sort of) scaling factor: 1 query mode: simple number of clients: 1 number of threads: 1 duration: 60 s number of transactions actually processed: 34017 tps = 566.948384 (including connections establishing) tps = 567.008666 (excluding connections establishing) statement latencies in milliseconds: 0.001879 \set nbranches 1 * :scale 0.000526 \set ntellers 10 * :scale 0.000490 \set naccounts 100000 * :scale 0.000595 \setrandom aid 1 :naccounts 0.000421 \setrandom bid 1 :nbranches 0.000480 \setrandom tid 1 :ntellers 0.000484 \setrandom delta -5000 5000 0.055047 BEGIN; 0.172179 UPDATE pgbench_accounts SET abalance = abalance + :delta WHERE aid = :aid; 0.135392 SELECT abalance FROM pgbench_accounts WHERE aid = :aid; 0.157224 UPDATE pgbench_tellers SET tbalance = tbalance + :delta WHERE tid = :tid; 0.147969 UPDATE pgbench_branches SET bbalance = bbalance + :delta WHERE bid = :bid; 0.123001 INSERT INTO pgbench_history (tid, bid, aid, delta, mtime) VALUES (:tid, :bid, :aid, :delta, CURRENT_TIMESTAMP); 0.957854 END; any ideas? Tigran. -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
