> Decrease the sort mem too much [8196] make the performance much slower
> so I use
> sort_mem = 16384
> and leave effective cache to the same value , the result is quite better
> but I
> should wait for tomorrow morning [official hour] to see the end result.
You could also profile your queries to see where those big sorts come
from, and maybe add some indexes to try to replace sorts by
index-scans-in-order, which use no temporary memory. Can you give an
example of your queries which make use of big sorts like this ?