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Archives of the TeradataForum
Message Posted: Mon, 10 Feb 2003 @ 15:14:30 GMT
Subj: | | Re: V2R5 Identity Column Population |
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From: | | Fred W Pluebell |
Because Teradata reserves a "batch" of identity values at a time and caches them (on each AMP for INSERT/SELECT) for better parallelism.
The "INCREMENTING BY" clause only applies within a batch. You have to make a tradeoff between "gaps" in the numbers and insert
performance.
The batch size is controlled by a dbscontrol "general" field (IdCol Batch Size), which defaults to 100,000. From your sample, I'd guess
your system has 20 AMPs and dbscontrol is set to the max of 1,000,000.
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