Re: Untested Developer Code - lack of concurrency testing

From: Stephane Faroult <>
Date: Tue, 12 May 2009 17:16:41 +0200
Message-ID: <>


    The home-made sequence generator (table that holds the next "sequence number") springs immediately to mind. Something I still see from time to time.

HTH Stéphane Faroult

kyle Hailey wrote:
> with one user and it runs fine and then gets put into production and
> only to hit a huge performance snafu. I'm putting together a demo on this kind of situation and was
> thinking of some examples. One example that came to mind is a Nesedt
> Loops join that hammers the root node of an index. Might work fine for
> one user, but when multiple users start running it, the query runs
> into cache buffers chains latch issues with the high concurrency
> access to the index's root block which might be resolved by doing a
> hash join or moving the lookup table to a hash cluster for example. Wondering if anyone else had good examples of developer code that
> worked fine with one user and broke in the multi user production
> environment.

Received on Tue May 12 2009 - 10:16:41 CDT

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