I've a table with about 34601755 rows ,when I execute 'update msg_table set type=0;' is very very slow, cost several hours, but still not complete?
Why postgresql is so slowly? Is the PG MVCC problem? But I try it on Mysql, the same table and rows, it only cost about 340 seconds. Any idea for the problem? My machine config: Memory 8G, 8 piece 15K disk , 2CPU(Quad-Core) AMD OS: Red Hat AS4 My postgres.conf main parameter is following: shared_buffers = 5GB # min 128kB or max_connections*16kB # (change requires restart) temp_buffers = 512MB # min 800kB work_mem = 400MB # min 64kB maintenance_work_mem = 600MB # min 1MB max_fsm_pages = 262144 # 2G min max_fsm_relations*16, 6 bytes each max_fsm_relations = 2000 # min 100, ~70 bytes each bgwriter_delay = 20ms # 10-10000ms between rounds bgwriter_lru_maxpages = 500 # 0-1000 max buffers written/round bgwriter_lru_multiplier = 2.0 # 0-10.0 multipler on buffers -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance