RE: Behavior of indexes after run a CLRPFM

["DeLong, Eric" <EDeLong@xxxxxxxxxxxxxxx>]

Is this a real index?  That is, it was created with a SQL CREATE INDEX
command?  Or is this a DDS based logical file?  I wonder how that index
is defined, whether it uses the MAINT(*IMMED) for the access path
maintenance attribute.

I also wonder if perhaps, immediately after your CLRPFM, if the system
might be maintaining that access path, making it unavailable to the
query optimizer.  

-Eric DeLong

-----Original Message-----
From: midrange-l-bounces@xxxxxxxxxxxx
[mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Rui Feliz
Sent: Thursday, January 20, 2011 10:18 AM
To: Midrange Systems Technical Discussion
Subject: Re: Behavior of indexes after run a CLRPFM

Hi.

Im working on AS/400. The only tool I know is PRTSQLINF. Anybody knows
another?
It's very strange, the index looks ok, but the optimizer don't uses it.
In
this situation, I drop the index and I create it again. After this, the
index is used by the process.
The only clue I have that perhaps causes problems is the CLRPFM  that I
run
in the beginnig of the process. The CLRPFM cleans the statistics of the
indexes?
Rui


On Thu, Jan 20, 2011 at 2:42 PM, <rob@xxxxxxxxx> wrote:

> I think there is an explain tool available in iNav which may help.  It
may
> decide that it was more economical to do a full table scan or some
such
> thing.  For example, if you did a CLRPFM and inserted one row, why
bother
> with an index?
>
>
> Rob Berendt
> --
> Group Dekko
> Dept 1600
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>
>
>
> From:   Rui <rmfeliz@xxxxxxxxx>
> To:     midrange-l@xxxxxxxxxxxx
> Date:   01/20/2011 09:22 AM
> Subject:        Behavior of indexes after run a CLRPFM
> Sent by:        midrange-l-bounces@xxxxxxxxxxxx
>
>
>
>
> Hello.
>
> Sometimes, when I run some SQL operations (like a select), the SQL
> Optimizer
> does not use the correct index.
> Before I load the table, I run a CLRPFM over it.
> Can the CLRPFM be responsable for the non-use of the indexes? The
RGZPFM
> fix it?
>
> Best Regards,
>
> Rui
>
>
>
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