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Thread: Index on points

Index on points

From
Holger Klawitter
Date:
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Hi there,

which operator class can I use in order to search points by distance like in:

SELECT p FROM tbl WHERE (p <-> point(0,0)) < 10;

- From what I've seen, there is none - which surprises me ...

Mit freundlichem Gruß / With kind regards
    Holger Klawitter
- --
lists <at> klawitter <dot> de
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Re: Index on points

From
Bruno Wolff III
Date:
On Tue, Jun 08, 2004 at 14:17:57 +0200,
  Holger Klawitter <lists@klawitter.de> wrote:
>
> Hi there,
>
> which operator class can I use in order to search points by distance like in:
>
> SELECT p FROM tbl WHERE (p <-> point(0,0)) < 10;
>
> - From what I've seen, there is none - which surprises me ...

You want to create a box that includes all points that might match
and use that to do an index search (using an rtree index) and then
check that the distance is really less than whatever.

Re: Index on points

From
Holger Klawitter
Date:
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Hi!

> > SELECT p FROM tbl WHERE (p <-> point(0,0)) < 10;
> You want to create a box that includes all points that might match
> and use that to do an index search (using an rtree index) and then
> check that the distance is really less than whatever.

Thanks for the hint!
I was just too confused about the lack of point operators to think about
alternatives...

Mit freundlichem Gruß / With kind regards
    Holger Klawitter
- --
lists <at> klawitter <dot> de
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