Marc Mamin <M.Mamin@xxxxxxxxxxxx> wrote: > Hello, > > > > UNION will remove all duplicates, so that the result additionally requires to > be sorted. Right, to avoid the SORT and UNIQUE - operation you can use UNION ALL > > Anyway, for performance issues, you should always start investigation with > explain analyze . ACK. Arguments to support bottom-posting... A: Because we read from top to bottom, left to right. Q: Why should I start my reply below the quoted text? A: Because it messes up the order in which people normally read text. Q: Why is top-posting such a bad thing? A: The lost context. Q: What makes top-posted replies harder to read than bottom-posted? A: Yes. Q: Should I trim down the quoted part of an email to which I'm replying? Andreas -- Really, I'm not out to destroy Microsoft. That will just be a completely unintentional side effect. (Linus Torvalds) "If I was god, I would recompile penguin with --enable-fly." (unknown) Kaufbach, Saxony, Germany, Europe. N 51.05082°, E 13.56889° -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance