In Apache Spark prior to 2.1, once a SQL query was run, there was no way to re-run it; all history was lost. Spark SQL introduced the "replay" functionality in Spark 2.1.0, enabling users to re-run any query they have already run. You can run a query once, save the query plan, and then later open the saved plan and run the query again. This type of history is stored in a table named sql query plan in the database. This can be seen by using the SHOW TABLES statement in the Spark SQL console.