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Message Posted: Tue, 26 Mar 2002 @ 23:25:58 GMT
I have a question regarding the "Note: Do not collect stats on large table because it is costly, and there is no real performance gain." stated in Teradata RDBMS for Unix - Performance Maximization Guide Release 3.0.0 Page 4.52.
We have several collect Stats jobs on large tables scheduled to run on a regular basis (weekly) and they run for many hours. If the above recommendation is true, then we should drop the existing stats and stop running the collect stats jobs on large tables. This will provide more resource for us to run other jobs.
I would like to find out the following:
1. Has anyone bypassed the collect Stats on large tables and does not see any performance degradation?
2. What is the lower bound table size(xxgb) that you consider as large table?
3. Teradata recommends to collect stats on all NUSIs since the Optimizer will not use NUSIs if there is no collect Stats on NUSIs. Does this recommendation also imply that we should not have any NUSI on large tables since these NUSIs for large tables will not be considered by Optimizer without any stats?
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