PG Hackers, What follows is iostat output from a TPC-H test on Solaris 10. The machine is creating indexes on a table which is 50G in size, so it needs to use pgsql_tmp for internal swapping:
tty md15 sd1 sd2 sd3 cpu tin tout kps tps serv kps tps serv kps tps serv kps tps serv us sy wt id 0 84 22526 1211 1 1024 1 5 0 0 0 5634 337 1 30 8 0 61 0 242 24004 1337 1 1024 1 5 0 0 0 6007 355 1 33 8 0 59 0 85 22687 1277 1 1024 1 5 0 0 0 5656 322 1 31 8 0 62 0 85 20876 1099 1 1024 2 9 0 0 0 5185 292 1 28 7 0 64 md15 is WAL (pg_xlog). sd3 is PGDATA. sd1 i pgsql_tmp. As you can see, we're getting a nice 23mb/s peak for WAL (thanks to forcedirectio) and database writes peak at 6mb/s. However, pgsql_tmp, which is being used heavily, hovers around 1mb/s, and never goes above 1.5mb/s. This seems to be throttling the whole system. Any suggestions on why this should be? Do we have a performance bug in the pg_tmp code? -- --Josh Josh Berkus Aglio Database Solutions San Francisco ---------------------------(end of broadcast)--------------------------- TIP 7: don't forget to increase your free space map settings
