Hi Arnau, >> - Is all the memory used by postgres ? > I'm not sure how to look at that (how could I do it?). In TOP you can see how much memory is used by postmaster process'es. > SD22-SINER5:~# top > top - 15:09:50 up 453 days, 11:47, 3 users, load average: 4.08, 3.90, 2.64 > Tasks: 70 total, 3 running, 67 sleeping, 0 stopped, 0 zombie > Cpu(s): 6.3% user, 37.1% system, 0.0% nice, 56.6% idle > Mem: 3748956k total, 3623988k used, 124968k free, 82976k buffers > Swap: 2097136k total, 13896k used, 2083240k free, 3283128k cached > The parameters related with memory usage of postgresql.conf all are the > default values (I haven't changed any value in the postgresql.conf file) > # - Memory - > #shared_buffers = 1000 > #sort_mem = 1024 > #vacuum_mem = 8192 > # - Free Space Map - > #max_fsm_pages = 20000 > #max_fsm_relations = 1000 > # - Kernel Resource Usage - > #max_files_per_process = 1000 > #preload_libraries = '' Take the suggestions from Scott Marlowe's mail, bump up the shared buffer memory usage. Apart from that there is a lot of really great info on the Varlena page he refers to. Go read it. >> - Run vmstat 1 and post the first 50 lines of data procs -----------memory---------- ---swap-- -----io---- --system-- ----cpu---- r b swpd free buff cache si so bi bo in cs us sy id wa 1 0 13900 118920 43584 3333540 0 0 1 0 0 0 6 37 57 0 1 4 13900 120592 42976 3330616 0 0 8096 5296 506 16905 55 20 24 0 <<stuff deleted>> NOW this is interesting. Your I/O is dominated by write operations. Do you make a lot of inserts ? What is the database used for ? What is the application in front of it ? >> - How large is your database (disk usage under postgres-x.x.x/data/base >> ) >SD22-SINER5:/var/lib/postgres# du --max-depth=1 -h >17G ./data >360K ./dumpall >17G . All this indicates a usage pattern where data is pumbed in at say 10Gigs an hour and is deleted after roughly two hours. Only 1/3 to ½ of the data is ever queried. Is this correct ? If this is the case then you may have to throw hardware at the problem. Raid 10 instead of raid 5, split the base over multiple raid devices and multiple controllers. > My settings are, do I should change anything else? > # - Query/Index Statistics Collector - > stats_start_collector = true > stats_command_string = true > #stats_block_level = false > stats_row_level = true > #stats_reset_on_server_start = true I run with: stats_command_string = on stats_block_level = on stats_row_level = on stats_reset_on_server_start = on That definatel gives you what you need. /John
