On 02/18/2018 06:37 AM, David Rowley wrote: > On 18 February 2018 at 12:35, hmidi slim <hmidi.slim2@xxxxxxxxx> wrote: >> Is there an other optimized solution to make a query such this: >> select * from ( >> select e.name, e1.name, e.id >> from establishment as e, establishment as e1 >> where e.id <> e1.id >> and e1.id = 1 >> and ST_DWithin(geom, ST_MakePoint(e1.longitude, e1.latitude)::geography, >> 1000)) as tmp inner join product as p on p.establishment_id = tmp.id > > You really should state what is wrong with the performance of the > above version and also include the EXPLAIN (ANALYZE, BUFFERS) of that > query. > > The version of PostgreSQL that you're running it on is also a good > thing to share. > > Details of the indexes which you've defined on the tables are also > useful information. It would especially be good to know if you've > added an index on product (establishment_id), for example. > There's actually a wiki page with overview of what should be included in "slow query" questions: https://wiki.postgresql.org/wiki/Slow_Query_Questions regards -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services