On Sun, 20 Feb 2005 12:35:02 -0300 (ART), Clodoaldo Pinto <clodoaldo_pinto@xxxxxxxxxxxx> wrote: > I made the same experience now with PG 8.01, FC3 and 512MB memory. The previous > was PG 7.4.6, FC2 and 1GB. > > The difference in performance between kernels 2.6.9-1.724 and 2.6.10-1.766 is > still huge. > > I notice that in 2.6.10 the function accesses the disk much more. > > Does anyone know what changes from 2.6.9 to 2.6.10 could cause this drop in > performance? > > Regards, Clodoaldo Pinto > This message did not connect to the original thread. So this is the reference: http://archives.postgresql.org/pgsql-general/2005-01/msg00569.php > 31 minutes in 2.6.10-1.8: > > select kstime(), update_ranking_usuarios(), kstime(); > kstime | update_ranking_usuarios | kstime > ---------------------+-------------------------+--------------------- > 2005-01-13 20:27:56 | | 2005-01-13 20:58:46 > (1 row) > > 5 minutes in 2.6.9-1.11: > > select kstime(), update_ranking_usuarios(), kstime(); > kstime | update_ranking_usuarios | kstime > ---------------------+-------------------------+--------------------- > 2005-01-13 23:24:30 | | 2005-01-13 23:29:26 > (1 row) > > The function: > > CREATE OR REPLACE FUNCTION update_ranking_usuarios() > RETURNS void AS > 'declare > linha record; > rank integer; > begin > rank := 0; > for linha in > select usuario > from usuarios_producao > where not anonymous --and n_time != 446 > order by pontos_0 desc > loop > rank := rank + 1; > update usuarios_producao > set rank_0 = rank > where usuario = linha.usuario > ; > end loop; > -- ---------------------------------------------------------- > rank := 0; > for linha in > select usuario > from usuarios_producao > where not anonymous --and n_time != 446 > order by pontos_0 + (( pontos_0 - pontos_7) / 7) desc > loop > rank := rank + 1; > update usuarios_producao > set rank_24 = rank > where usuario = linha.usuario > ; > end loop; > -- ---------------------------------------------------------- > rank := 0; > for linha in > select usuario > from usuarios_producao > where not anonymous --and n_time != 446 > order by pontos_0 + pontos_0 - pontos_7 desc > loop > rank := rank + 1; > update usuarios_producao > set rank_7 = rank > where usuario = linha.usuario > ; > end loop; > -- ---------------------------------------------------------- > rank := 0; > for linha in > select usuario > from usuarios_producao > where not anonymous --and n_time != 446 > order by pontos_0 + (( pontos_0 - pontos_7) * 30 / 7) desc > loop > rank := rank + 1; > update usuarios_producao > set rank_30 = rank > where usuario = linha.usuario > ; > end loop; > return; > end;' > LANGUAGE 'plpgsql' STABLE; > > Part of postgresql.conf: > > shared_buffers = 3000 # min 16, at least max_connections*2, 8KB > each > sort_mem = 49152 # min 64, size in KB > vacuum_mem = 32768 # min 1024, size in KB > vacuum_mem = 32768 > max_fsm_pages = 300000 # min max_fsm_relations*16, 6 bytes each > fsync = false > wal_buffers = 256 > checkpoint_segments = 32 # in logfile segments, min 1, 16MB each > > The log file shows only a long list of: > > LOG: recycled transaction log file "0000010A000000D0" > LOG: recycled transaction log file "0000010A000000CF" > LOG: recycled transaction log file "0000010A000000C9" > ... > > Regards, Clodoaldo Pinto > ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster
