Re: SELECT DISTINCT too slow

Miroslav ?ulc wrote:
> Well, "key" is not primary key from another table. It is just a column
> in pair "key" => "value".
> The structure of the table is this:
> 
> Id (primary key)
> MRTPContactId (id of contact from table MRTPContact)
> Key (key from pair key => value)
> Value (value from pair key => value)
> 
> So I want the get the list of keys used in the table.

The plan you get is the most efficient possible for that query.  If you
had a table of possible keys (which should of course be FK of "Key"),
you could get a much faster version :-)

-- 
Alvaro Herrera                                http://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.