Re: Indexes vs Logical Files

["Diego E. KESSELMAN" <diegokesselman@xxxxxxxxx>]

Greg,

Can you post the IGNORE_DERIVED_INDEX value in your QAQQINI?


On 13/10/23 07:09, Greg Wilburn wrote:
> The physical file does not have keys.  Only the LF have keys.
>
> -----Original Message-----
> From: MIDRANGE-L <midrange-l-bounces@xxxxxxxxxxxxxxxxxx> On Behalf Of Gavin Inman
> Sent: Friday, October 13, 2023 8:52 AM
> To: Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxxxxxxxx>
> Subject: Re: Indexes vs Logical Files
>
> Years ago it was explained to me that if the physical has keys, it's
> forced to use the older database engine.  Unless something has changed,
> I believe that's still true today.
>
> Gavin.
>
> On 10/13/2023 8:47 AM, Greg Wilburn wrote:
>
> I've been using Index Advisor and Run Sql Scripts "Run and Explain" to analyze some of our queries.  I'm looking for increased performance.
>
> I have a large file/table OEBOXCBX with a logical files defined with the following keys:
>
> LF #1: BXCOM#, BXORD#, BXREL#, BXBOX#, BXPRT#
> LF #2: BXCOM#, BXORD#, BXREL#, BXBXNO, BXPRT#
>
> I ran an SQL statement over a complex SQL view that contains this file.  RSS Run and Explain recommended the following index:
> CREATE INDEX ASTHHOBJ/OEBOXCBX_IDX
>       ON ASTHHOBJ/OEBOXCBX (BXCOM# ASC, BXORD# ASC, BXREL# ASC) UNIT ANY KEEP IN MEMORY NO;
>
> My question is why the SQE wouldn't use one of the existing logical files as an index?  As an RPG guy, this makes no sense to me.
>
> TIA,
> Greg
>
> [Logo]<https://www.totalbizfulfillment.com/>     Greg Wilburn
> Director of IT
> 301.895.3792 ext. 1231
> 301.895.3895 direct
> gwilburn@xxxxxxxxxxxxxxxxxxxxxxx<mailto:gwilburn@xxxxxxxxxxxxxxxxxxxxxxx>
> 1 Corporate Dr
> Grantsville, MD 21536
> www.totalbizfulfillment.com<http://www.totalbizfulfillment.com>