Re: Direction for Keeping Web DB up to date

[Charles Wilt <charles.wilt@xxxxxxxxx>]

Scott,

I'd still strongly consider getting rid of the MS SQL Server.  You may
be surprised at how fast the i can return data from a denormalized
view with the proper indexes over the base tables.  If that's not good
enough, you could simply create denormalized tables on the i5 that are
kept updated via triggers on the production tables.  Replication
between multiple tables on the same DB is easy compared to replicating
the data to another DB.

At least you're looking at a replication package.  Note that some
packages offer the ability to use triggers or journals.

If none of your files are journalled now, then journalling will
definitely add some overhead.  However, there are ways to minimize the
overhead.  In addition, IBM offers a "Pseudo Journal" tool that you
can run to estimate the overhead.
http://systeminetwork.com/article/use-pseudo-journal-toolset-estimate-journaling-requirements
http://www-03.ibm.com/systems/i/software/db2/journalperfutilities.html

HTH,
Charles


On Fri, Aug 7, 2009 at 8:58 AM, Scott Johnson<sjohnson@xxxxxxxxxxxxxxx> wrote:
> One think that I failed to mention that may or may not affect your thoughts
> is that the tables between the i5 side and MS SQL side are not 1 to 1.
> There are cases where one row/column/table on the i5 side can apply to
> multiple rows/columns/tables on the MS SQL side.  And where multiple
> rows/columns/tables on the i5 side apply to one row/column/table on the MS
> SQL side.  This is due to de-normalization and such on the web side to
> improve performance and data availability.
>
> I am also concerned with the performance hit between the two proposed
> solutions.  Since the programs (not including the actual trigger program)
> used in the trigger solution are just batch jobs, I can control the
> resources they get.  That does not seem to be the case with journaling.
>
>
> Thanks,
>    Scott J.
>
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