Introduction
Statistics, by definition, are the collection, organization, analysis, interpretation, and presentation of data.
-Source Wikipedia
The mathematical study of the theoretical nature of such distributions and tests.
-Source Dictionary
In Teradata, the STATISTICS
command will gather and store demographic data for one or more columns or indices of a table or join index.
Statistics help in analyzing things based on aggregation of data. They turn data into useful information so that actions can be taken or predictions can be made.
The same goes for Teradata. The Teradata optimizer uses statistics to develop plans for query executions:
The optimizer generates several plans before choosing the most optimized one, based on cost. The estimations that we see in explain plans are derived from data demographics of the table which the optimizer collects while doing a statistics collection.
Stats collection can be a resource-intensive operation if large tables are involved; hence, it needs to be scheduled...