From: | Martijn van Oosterhout <kleptog(at)svana(dot)org> |
---|---|
To: | Tzahi Fadida <Tzahi(dot)ML(at)gmail(dot)com> |
Cc: | pgsql-hackers <pgsql-hackers(at)postgresql(dot)org> |
Subject: | Re: Planning without reason. |
Date: | 2006-06-23 13:14:47 |
Message-ID: | 20060623131447.GD8900@svana.org |
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Lists: | pgsql-hackers |
On Fri, Jun 23, 2006 at 03:57:19PM +0300, Tzahi Fadida wrote:
> R contains indices but not on all attributes or not on
> all ordered subset of keys.
>
> Query example:
> (SELECT * FROM R
> WHERE a=3, b=6,. ...)
> UNION
> (SELECT * FROM R
> WHERE b=5, d=2,. ...)
> UNION
> ....
> And lots of unions.
Do you need UNION, or do you actually mean UNION ALL?
Also, couldn't you just do:
SELECT * FROM R
WHERE (a=3, b=6, ...)
OR (b=5, d=2, ...)
etc
> I am currently just writing the query as a string and open a cursor.
> Is there a simple way to use Datums instead of converting the attributes to
> strings to create a plan for SPI.
> 10x.
I imagine SPI_prepare() and SPI_execp() would be used for this.
Have a nice day,
--
Martijn van Oosterhout <kleptog(at)svana(dot)org> http://svana.org/kleptog/
> From each according to his ability. To each according to his ability to litigate.
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