RE: SQL Cursor Questions(and query 400)

[Joel Fritz <JFritz@xxxxxxxxxxxxxxxx>]

No, sometimes it will use an existing access path as long as the sort (group
by) is identical to the key for the logical.

> -----Original Message-----
> From: pytel@us.ibm.com [mailto:pytel@us.ibm.com]
> Sent: Friday, November 19, 1999 11:27 AM
> To: MIDRANGE-L@midrange.com
> Subject: RE: SQL Cursor Questions(and query 400)
> 
> 
> I may be wrong, but I seem to recollect hat Query will never 
> use existing
> access path - unless you point it directly to LF.
> 
> Best regards
>     Alexei Pytel
> 
> 
> Joel Fritz <JFritz@sharperimage.com> on 11/19/99 10:45:11 AM
> 
> Please respond to MIDRANGE-L@midrange.com
> 
> To:   "'MIDRANGE-L@midrange.com'" <MIDRANGE-L@midrange.com>
> cc:
> Subject:  RE: SQL Cursor Questions(and query 400)
> 
> 
> 
> 
> Does this apply to Query400?  I know I've improved the batch 
> performance of
> queries dramatically by pointing them at an existing logical 
> file when they
> built an access path when pointed at an unkeyed physical.
> 
> > -----Original Message-----
> > From: pytel@us.ibm.com [mailto:pytel@us.ibm.com]
> > Sent: Thursday, November 18, 1999 6:25 PM
> > To: MIDRANGE-L@midrange.com
> > Subject: Re: SQL Cursor Questions
> >
> >
> >
> >
> >
> /*                SNIP                                             */
> >
> > SQL does not care, whether you address PF or LF - it will always use
> > underlying data in the way it considers is most optimal.
> > The difference between SQL in interactive session and SQL
> > imbedded in a
> > program is that optimization goals are slightly different.
> > By defaut, interactive SQL is biased to returning first
> > screenful of data
> > as fast as possible, and imbedded SQL is geared to reduce
> > entire processing
> > time. This will explain why access path was used for
> > interactive and not
> > for batch - arrival access path may be more efficient if
> > large subset of
> > file records is selected.
> >
> >
> > Best regards
> >     Alexei Pytel
> >
> >
> >
> >
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