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Why we use materialized view in distributed database?
In distributed environments, you can use materialized views to replicate data at distributed sites and to synchronize updates done at those sites with conflict resolution methods. These replica materialized views provide local access to data that otherwise would have to be accessed from remote sites.
What is materialized view in database?
In computing, a materialized view is a database object that contains the results of a query. Whenever a query or an update addresses an ordinary view’s virtual table, the DBMS converts these into queries or updates against the underlying base tables.
How we can refresh materialized view?
REFRESH MATERIALIZED VIEW completely replaces the contents of a materialized view. To execute this command you must be the owner of the materialized view. The old contents are discarded.
What do I need to know about Materialized View Refresh?
The collection level defines the amount of statistics that the database collects for materialized view refresh operations. You can either collect basic statistics or more detailed information such as the parameters used and the SQL statements run during the materialized view refresh operation.
Can a materialized view be purged from the database?
Materialized views for which the default settings are not overridden will continue to use the system default settings. You can specify that refresh statistics must never be purged from the database by setting the retention period to -1. To specify a new default retention period for the entire database:
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.
Why do we need materialized views in Oracle?
I have been researching using materialized views for data aggregation and reporting purposes for a company that is largely centered around transactions (using an Oracle db). The current reporting system is dependent upon a series of views that obscure a lot of the complex data logic of the application.