Re: DB View performance

Rob Berendt <[email protected]>
Newsgroups gmane.comp.hardware.ibm.midrange
Message-ID <CAPJ+qQNG=sHB9wd5+E2YHs2Su2GEFzJU1z7xZn_SrLRUg6dNYw@mail.gmail.com>
Did you use the tool to retrieve the SQL source of your old view and
compare it to the one you recreated without the new column?

On Wed, May 27, 2026 at 1:42 PM Greg Wilburn <
[email protected]> wrote:

> I have a relatively complicated database view that references other
> views.  Back in 2020, I was able to create some indexes to improve
> performance when this view was used.
>
> Without going into a lot of detail, I added a column to the view to simply
> count the lines in the primary table (the view already groups results).  I
> did this generating the DDL from ACS Schemas tool.  Using run sql scripts,
> I did a "create or replace view" after adding the column.  This change
> killed the performance, so I removed the new column and ran "create or
> replace view" again.
>
> Now to the odd part... the performance was still horrible.  I didn't know
> what to do, so I restored the view from our cloud backup - this fixed the
> performance issue.
>
> My question is why?  What is happening behind the scene that I'm not
> considering?
> I honestly can't imagine that adding a "count(myfield) as mynewfield"
> column would dramatically affect the performance.
>
> Greg
> [Logo]<https://www.totalbizfulfillment.com/>    Greg Wilburn
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> 301.895.3792 ext. 1231
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