Statistical information is vital for the optimizer when it builds query plans. But collecting statistics can involve time and resources. By understanding and combining several different statistics gathering techniques, users of Teradata can find the correct balance between good query plans and the time required to ensure adequate statistical information is always available.
This recently-updated compilation of statistics collection recommendations are intended for sites that are on any of the Teradata Database 14.10, 15.0, or 15.10 software release levels. Some of these recommendations apply to releases earlier than Teradata Database 14.10 and some rely on new features available starting in Teradata Database 14.10. Statistics collection functionality in the Teradata Database works the same in 14.10, 15.0 and 15.10 releases.
For greater detail on collecting statistics for Teradata Database 14.10, see the orange book titled: Teradata Database 14.10 Statistics Enhancements by Rama Krishna Korlapati.
Contributors: Carrie Ballinger, Rama Krishna Korlapati, Paul Sinclair, September 11, 2014
Collect Full Statistics
Can Rely on Dynamic AMP Sampling
Collect Multicolumn Statistics
General Suggestions for the Statistics Collection Process
New Recommendations for Teradata Database 14.10
EXPLAIN SELECT DISTINCT NUPI-column FROM table;
 Any column which is over 95% unique is considered as a nearly-unique column.
 Dynamic AMP sampling is sometimes referred to as random AMP sampling.
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