Curious, I ran this one using set explain:

SELECT MIN(colno) FROM syscolumns WHERE colno>=1 AND colno>1

Estimated Cost: 400
Estimated # of Rows Returned: 1

1) informix.syscolumns: INDEX PATH

(1) Index Keys: tabid colno (Key-Only)
Index Key Filters: (informix.syscolumns.colno >= 1 )

The AND is being dropped. It would seem that the optimizer looks for simplifications that can be applied and in this case is dropping the more restritive filter. Of course I could be giving the optimizer too much credit.

> -----Original Message-----
> From: informix-list-bounces@iiug.org
> [mailto:informix-list-bounces@iiug.org]On Behalf Of Andrew Ford
> Sent: Wednesday, May 07, 2008 10:59 AM
> To: informix-list@iiug.org
> Subject: Re: reliability?
>
>
> > Same on HPUX 11.11, IDS10.00.FC6
> >
>
> Not the same result on IDS 11.10.UC1, Red Hat Enterprise
> Linux ES release 4.
>
> > echo "SELECT MIN(colno) FROM syscolumns WHERE colno>=1 AND
> colno>1" |
> > dbaccess sysmaster
>
> Database selected.
>
>
>
> (min)
>
> 2
>
> 1 row(s) retrieved.
>
>
>
> Database closed.
>
>
> Andrew
>
>
> _______________________________________________
> Informix-list mailing list
> Informix-list@iiug.org
> http://www.iiug.org/mailman/listinfo/informix-list
>




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