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Message Posted: Tue, 05 Nov 2002 @ 16:43:06 GMT

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My guess is that the performance issue is probably not related to Fallback.

I would suggest that you look first at your selection of Primary Indices. If you are using Non-Unique Primary Indexes, it may be that you are incurring "hash collisions". In other words, there are many rows with the same primary index value (or at least the same primary index hash value). When this happens, the DBMS will check each new row with the same primary index against every other existing row (assuming SET tables) with the same primary index to ensure that each row is unique. As more rows with the same PI value exist, this duplicate row check takes longer.

Check the frequency of rows per unique PI value. If there are 1000's of rows for a given PI value, this may be your problem. If this is indeed the case, you can:

1) Change your PI for the tables affected.

2) Change the table from a "SET" table to a "MULTISET" table. This eliminates the duplicate row check.

Hope this helps.

Thomas F. Stanek
TFS Consulting

www.tfsconsulting.com

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