Materialized Views are very useful to increase the performance of frequently executed queries. In many database applications, Materialized Views are accessed directly using SQL. However, the use of Query Rewrite is much more elegant and flexible: The optimizer decides independently whether a suitable Materialized View can be used to accelerate the query. The goal is to be able to improve the performance of different queries with the smallest possible number of Materialized Views. Query Rewrite offers excellent possibilities for this. Although Query Rewrite is available in Oracle databases for a long time, the feature is still unknown to many Oracle developers or is not used due to its complexity. This presentation shows the power of Query Rewrite, how it is configured correctly, what has to be considered when creating Materialized Views and which new features have been introduced in versions 12.2, 18c and 19c.
Speaker: Dani Schnider
Title: “Query Rewrite: The Supreme League of Materialized Views”
Recorded on: Wednesday, April 1st 2020