2014-10-05 21:57 GMT+03:00 Andrey Lizenko <[email protected]>:
> Increasing of 'effective_cache_size' leads to similar thing with
> mergejoin,
> other options (work_mem, shared_buffers. etc) do not change anything.
>
I think increasing `work_mem` should have effects, as plan with `Nested
Loop` is using disk-based sort.
Increase it till you'll stop seeing `external sort` in the EXPLAIN output.
Something like '10MB' should do.
Also, it'd be handy if you could provide `EXPLAIN (analyze, buffers)`
output along with the results of these queries:
SELECT name,setting,source FROM pg_settings WHERE name ~ 'cost' AND NOT
name ~ 'vacuum';
SELECT name,setting,source FROM pg_settings WHERE NOT source IN
('default','override');
And describe your setup: what OS? how much RAM? what kind of disks? RAID?
--
Victor Y. Yegorov
