In previous releases on-commit materialized view refreshes were serialized. If multiple session triggered an on-commit refresh of the same materialized view, they were performed one at a time. This could impact performance on busy tables. In Oracle 23ai/26ai materialized view refreshes can be performed concurrently for on-commit fast refreshes by adding the clause. - Materialized View Concurrent Refreshes in Oracle Database 23ai/26ai

In Oracle 23ai/26ai materialized views support query rewrites for SQL statements using ANSI or Oracle style joins. This means your materialized view definitions and SQL statements can use either join syntax and still allow query rewrites. - Materialized View Support for ANSI Joins in Oracle Database 23ai/26ai

Semi-Join Materialized View Rewrite is a unique form of query rewrite introduced in Oracle Database 23ai/26ai. - About Semi-Join Materialized View Rewrite

In Oracle database 23ai/26ai Logical Partition Change Tracking (LPCT) allows materialized view staleness to be tracked at the level of a logical partition. - Logical Partition Change Tracking (LPCT) for Materialized Views in Oracle Database 23ai/26ai

Oracle 18c introduced the ability to use the refreshes of materialized views built with function calls. Oracle 19c can perform query rewrites of statements using some SQL/JSON functions ( , ) to use a materialized view containing an appropriate call. Oracle 23ai/26ai introduces a number of enhancement for this functionality. - Fast refreshes are supported on a wider variety of materialized views. - Fast refreshes support multi-table materialized join views (MJVs) and materialized aggregate views (MAVs). In the previous release we were limited to a single table materialized join views. - Query rewrite support has been improved to support the new variations described above. The documentation of these improvements is rather sparse, which is also true of all previous iterations of this functionality. For more information see: Hope this helps. Regards Tim...