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How do I automatically refresh a materialized view?
view group to do the refresh. You can also use m. view log to keep track of all the dml and the have it propagated to the m. view with a fast refresh on a remote database through the db link.
How often are materialized views refreshed?
Unlike indexes, materialized views are not automatically updated with every data change. They must explicitly be refreshed, either on every commit, on a periodically time schedule or – typically in data warehouses – at the end of an ETL job.
How do I change the refresh time of a materialized view?
ALTER MATERIALIZED VIEW emp_data REFRESH COMPLETE START WITH TRUNC(SYSDATE+1) + 9/24 NEXT SYSDATE+7; The START WITH value establishes the next automatic refresh for the materialized view to be 9:00 a.m. tomorrow.
Is there a way to refresh materialized views in Oracle?
Oracle provides flexible ways to refresh materialized views: you can refresh them full or incremental; you can refresh them on demand or at the commit time in the source table. When the size of the materialized view grows, one needs to explore ways to perform the refresh faster.
Can a distributed MView be refreshed in parallel?
Distributed mviews cannot be refreshed in parallel. The Oracle documentation for Restrictions on Parallel DML states, “A DML operation cannot be executed in parallel if it is in a distributed transaction or if the DML or the query operation is on a remote object.”
When is materialized view not compatible with base table?
When a materialized view is created on both base tables with timestamp-based materialized view logs and base tables with commit SCN-based materialized view logs, an error (ORA-32414) is raised stating that materialized view logs are not compatible with each other for fast refresh.
How are job queues used to refresh materialized views?
Job queues can be used to refresh multiple materialized views in parallel. If queues are not available, fast refresh sequentially refreshes each view in the foreground process. To make queues available, you must set the JOB_QUEUE_PROCESSES parameter.