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Archives of the TeradataForumMessage Posted: Mon, 27 Jun 2011 @ 09:56:52 GMT
Anomy.Anom wrote:
You easily hit the limit of 64k partitions when you start using multi-level partitioning, so this forces less-than-daily partitions.
AFAIK for FTS/SI-lookup/USI-maintenance there's no impact. But if the partitioning column is not part of the PI: - any PI access without specifying the partitioning column is slower than before because every partition has to be probed to find the matching RowHash. The performance impact correlates to the number of partitions (you could add an NUSI to avoid that). - joins to non-partitioned tables using the PI only without specifying the partitioning column will be slower. The performance impact correlates to the number of partitions participating in the join (i.e. after partition elimination) The potential performance improvements of partitioning might get larger when you got more partitions, but those potential disadvantages, too :-) So just create as much partitions as neccessary (based on your access pattern). Dieter
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