Creating and using a materialized view
You can create a materialized view of a query to calculate and store results of an expensive operation, such as a particular join, that you repeatedly run. When you issue queries specified by that materialized view, the optimizer rewrites the query based on it. This action saves reprocessing. Query performance improves.
In this task, you create and populate example tables. You create a materialized view of a join of the tables. Subsequently, when you run a query to join the tables, the query plan takes advantage of the precomputed join to accelerate processing. This task is over-simplified and is intended to show the syntax and output of a materialized view, not to demonstrate accelerated processing that results in a real-world task, which would process a large amount of data.