Marius Andreiana wrote:

On Tue, 2004-08-03 at 08:05 -0400, Merlin Moncure wrote:

Trying to run this query:
select * FROM trans
WHERE query_id NOT IN (select query_id FROM query)

but it will remain like that forever (cancelled after 30 min).

explain analyze actually runs the query to do timings. Just run explain and see what you come up with. More than likely there is a nestloop in there which is causing the long query time.

Try bumping up shared buffers some and sort mem as much as you safely

Thank you, that did it!

shared_buffers = 3000           # min 16, at least max_connections*2, 8KB each
sort_mem = 128000               # min 64, size in KB

128 MB for sort_mem is too much, consider that in this way each backend can use 128 MB for sort operations... Also shared_buffers = 3000 means 24MB that is not balanced with the 128MB needed for sort... Try to bump up 128 MB for shared_buffer ( may be you need to instruct your OS to allow that ammount of shared memory usage ) and 24MB for sort_mem.

Gaetano Mendola

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