The Statistics Cache
The statistics cache minimizes Parser overhead required to optimize queries. It does this by caching statistics, UDI counts, and other demographic information from the Data Dictionary that has been fetched during a session to optimize SQL queries.
When the Optimizer requires statistics to process a table, it first retrieves the summary information for all the statistics on the table. Teradata Database stores the retrieved demographic data in the statistics cache, where it is expected to remain cached for an extended period. The purpose of the statistics cache is to retain statistics that have been fetched to optimize queries in memory for as long as possible.
You can use the DBS Control field NumStatisticsCacheSegs to change the size of the statistics cache. See Teradata Vantage™ - Database Utilities , B035-1102 for further information about fine tuning the statistics cache.
Unlike the dictionary cache, Teradata Database does not purge the statistics cache periodically, purging it only when operations to collect or drop statistics occur.