On Thu, Jul 19, 2012 at 4:43 PM, Thomas Kellerer <spam_ea...@gmx.net> wrote: > delete from some_table > where id not in (select min(id) > from some_table > group by col1, col2 > having count(*) > 1); > > (It's the usual - at least for me - "get rid of duplicates" statement)
If you want to remove duplicates you can do it this way. DELETE FROM some_table USING some_table AS s WHERE some_table.col1 = s.col1 AND some_table.col2 = s.col2 AND some_table.id < s.id; The query plan should be better than one with the sub query and NOT IN. ps. May be this example is worth to append to the documentation? -- Sergey Konoplev a database architect, software developer at PostgreSQL-Consulting.com http://www.postgresql-consulting.com Jabber: gray...@gmail.com Skype: gray-hemp Phone: +79160686204 -- Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-sql