Hello, I have table with 37 million entries the whole table has a size of 2.3 GB Although I have set the work_mem to 10 GB I see the an unexpected external sort Disk in Explain Analyze for around 650MB of data EXPLAIN ANALYZE SELECT application_id, price_tier FROM application_prices order by application_id, created_at; QUERY PLAN ---------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=5284625.89..5378196.50 rows=37428244 width=8) (actual time=36972.658..40618.161 rows=37428244 loops=1) Sort Key: application_id, created_at Sort Method: external sort Disk: 658568kB -> Seq Scan on application_prices (cost=0.00..576597.44 rows=37428244 width=8) (actual time=0.012..6259.923 rows=37428244 loops=1) Total runtime: 42999.882 ms (5 rows) Has anyone an idea what I'm missing ? Thanks Manuel -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general