COLLECT STATISTICS (QCD Form) Does Not Collect Statistics For The Optimizer - Analytics Database - Teradata Vantage

SQL Data Manipulation Language

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
2024-04-05
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lifecycle
latest
Product Category
Teradata Vantage™

Unlike the standard COLLECT STATISTICS statement, COLLECT STATISTICS (QCD Form) does not write the statistics it collects into the data dictionary for use by the Optimizer. The COLLECT STATISTICS (QCD Form) writes its statistics into the TableStatistics table of the specified QCD database, where the information is used by various database query analysis tools to perform index analysis and validation.

Because COLLECT STATISTICS (QCD Form) does not write its statistics to the data dictionary, it does not place locks on dictionary tables. Through appropriate control of the sample size, you can collect sample statistics for index analysis during production hours without a noticeable negative effect on system performance.