On Sun, Sep 21, 2008 at 06:17:39PM +0400, Anton Belyaev wrote: > Geometry types and functions use R-tree indexes anyways. > > I can rephrase the query using geometry language of Postgres: > SELECT * FROM towns WHERE towns.coordinates <@ box(alt1, long1, alt2, > long2) ORDER BY population LIMIT 10; > > And the questions about population remain the same: > How to avoid examination of all the towns in the rectangle knowing > that we need only 10 biggest?
I don't know if it solves your problem, but you should be able to do a multi-column GiST index with both the position data and the population data in it. However, I'm unsure if postgresql will correctly use the index to solve the order by... Have a nice day, -- Martijn van Oosterhout <[EMAIL PROTECTED]> http://svana.org/kleptog/ > Please line up in a tree and maintain the heap invariant while > boarding. Thank you for flying nlogn airlines.
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