RE: query400 question

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I believe that how query selects records changed around V4R2.  What I think
happens is when query has to build a hash table then all records are
selected and select / omit rules are applied after the fact.

> -----Original Message-----
> From: MacWheel99@aol.com [SMTP:MacWheel99@aol.com]
> Sent: Tuesday, November 27, 2001 1:16 PM
> To:   midrange-l@midrange.com
> Subject:      Re: query400 question
>
> Interesting observation.
> I thought query/400 always read all records before deciding which ones it
> did
> not need, unlike RPG & SQL that only read the ones that you specify.
>
> So for example, I do a calculated field, then select only those records in
> which the divide by field is not zero & the query bombs because of divide
> by
> zero, because it is doing the divide before it does the not zero, but if I
> make the math divide by (whatever value + 0.00001) it correctly excludes
> the
> whatever value when zero & does not blow up again until we have a case of
> that value being 0.00001-
>
> > hey all,
> >
> >  quick question:  does anyone know when/what makes query/400 decide it
> must
> >  read all records for the query before displaying the first page?
> >
> >  I use query a lot for quick one-off reports, mostly for my own
> analysis,
> >  and in some complicated querys (joins, sorting on fields from different
> >  files, etc) the query reads through all records before displaying the
> first
> >  page.
> >
> >  sometimes, by omitting just one field from the sort, it won't have to
> read
> >  the whole thing.
> >
> >  just curious,  TIA.
> >
> >  rick
> >
>
>
> MacWheel99@aol.com (Alister Wm Macintyre) (Al Mac)
> BPCS 405 CD Manager / Programmer @ Global Wire Technologies Incorporated
> http://www.globalwiretechnologies.com = new name same quality wire
> engineering company: fax # 812-424-6838
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