On Mon, 4 Aug 2003, Manfred Koizar wrote: > On 01 Aug 2003 11:04:10 -0700, Jenny Zhang <[EMAIL PROTECTED]> wrote: > >A sample OSDL-DBT3 test result report can be found at: > >http://khack.osdl.org/stp/276912/ > > > >Your comments are welcome, > > | effective_cache_size | 1000 > > With 4GB of memory this is definitely too low and *can* (note that I > don't say *must*) lead the planner to wrong decisions. > > | shared_buffers | 15200 > > ... looks reasonable. Did you test with other values? > > | sort_mem | 524288 > > This is a bit high, IMHO, but might be ok given that DBT3 is not run > with many concurrent sessions (right?). > http://khack.osdl.org/stp/276912/results/plot/vmstat_swap.png shows > some swapping activity towards the end of the run which could be > caused by a too high sort_mem setting.
Sorry, my last email shot off out of the gun before it was completed... To repeat: Don't forget to set effective_cache_size the same way as shared buffers (i.e. it's in 8k blocks for most systems.) If you have a machine with 4 gig ram, and 3 gigs is available as disk cache, then divide out 3 gigs by 8k to get the right number. My quick calculation shows that being about 393216 blocks. ---------------------------(end of broadcast)--------------------------- TIP 1: subscribe and unsubscribe commands go to [EMAIL PROTECTED]
