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Message Posted: Fri, 05 Jan 2007 @ 20:57:43 GMT
It is best to include the PPI column in the filter (where clause). It is also most desirable to include all of the primary index columns on the filter. I suggest you look at the explains, this is easiest way to discover best method. Results of this will possibly cause modeling or index choices changes depending on columns available, volume of changes, other types of access, etc.
Also don't forget to take these factors into account before deciding how to apply updates.
1) Impacts of updating columns that are part of an index are more expensive as the index must be maintained.
2) Join indexes on the table that are updated might be updated or rebuilt.
3) Updating the PPI column will cause data to be moved which of course is more expensive.
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