=?UTF-8?Q?Ondrej_Ivani=C4=8D?= <ondrej.ivanic@xxxxxxxxx> writes: > work_mem is set to 4 000 000 kb and I do not understand why few > queries (3 and 5) used disk and the rest fit were able to data into > memory. The on-disk representation of sort data is quite a bit more compact than the in-memory representation. So where it says that 3.5GB of disk were needed, it's not a surprise that the memory requirement would have exceeded 4GB to do the sort in-memory. If you want to know what the conversion factor is for your particular dataset, try doing the query with small and large work_mem so you can see what is reported as the amount of space needed each way. regards, tom lane -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
