Re: index structure for 114-dimension vector - Mailing list pgsql-performance

From Jeff Davis
Subject Re: index structure for 114-dimension vector
Date
Msg-id 1177105284.28383.31.camel@dogma.v10.wvs
Whole thread Raw
In response to index structure for 114-dimension vector  (Andrew Lazarus <andrew@pillette.com>)
Responses Re: index structure for 114-dimension vector
List pgsql-performance
On Fri, 2007-04-20 at 12:07 -0700, Andrew Lazarus wrote:
> I have a table with 2.5 million real[] arrays. (They are points in a
> time series.) Given a new array X, I'd like to find, say, the 25
> closest to X in some sense--for simplification, let's just say in the
> usual vector norm. Speed is critical here, and everything I have tried
> has been too slow.
>
> I imported the cube contrib package, and I tried creating an index on
> a cube of the last 6 elements, which are the most important. Then I

Have you tried just making normal indexes on each of the last 6 elements
and see if postgresql will use a BitmapAnd to combine them?

Regards,
    Jeff Davis




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