Re: index on two tables or Howto speedup max/aggregate-function

On Tue, Oct 13, 2009 at 9:59 AM, Michael Schwipps <msc.listen@online.de> wrote:

Hi,

I want to select the last contact of person via mail.
My sample database is build with the following shell-commands

| createdb -U postgres test2
| psql -U postgres test2 < mail_db.sql
| mailtest.sh | psql -U postgres

I call to get the answer

| SELECT address, max(sent) from mail inner join
| tomail on (mail.id=tomail.mail) group by address;