Collecting Statistics on Skewed Data - Analytics Database - Teradata Vantage

Database Administration

Deployment
VantageCloud
VantageCore
Edition
Enterprise
IntelliFlex
VMware
Product
Analytics Database
Teradata Vantage
Release Number
17.20
Published
June 2022
Language
English (United States)
Last Update
2023-11-03
dita:mapPath
pgf1628096104492.ditamap
dita:ditavalPath
qkf1628213546010.ditaval
dita:id
ujp1472240543947
lifecycle
latest
Product Category
Teradata Vantageā„¢

For collecting statistics on skewed data, the Optimizer can accommodate exceptional values. Statistics take into account the most nonunique value in a table and the most nonunique value in a value range.

Without statistics, the system relies on dynamic AMP sampling, which can be quite inaccurate when the table is small or unevenly distributed. Small tables often distribute unevenly.