MQT used summary

Contains a row of information for each materialized query table that an SQL statement used. This can be used to quickly tell if any of the materialized query tables were used to improve the performance of a query. MQTs may be used to improve the performance of queries that are repeatedly run where the results of the query do not have to contain up to the second information. This information can be used to determine how often an MQT was used by in the statements that were monitored. MQTs that are never (or very rarely) used should be dropped. Even though they do not affect the performance of inserts, updates, and deletes to the tables referenced in the MQT, MQTs do cause the optimizer to spend a bit more time when optimizing a query. Before dropping the MQT you may also want to look at the last used date in the Description information for the MQT and in the Show MQTs information for the tables referenced in the MQT.