Oracle maintains the data in materialized views by refreshing them after changes are made to their master tables. The refresh method can be incremental (fast refresh) or complete. For materialized views that use the fast refresh method, a materialized view log or direct loader log keeps a record of changes to the master tables.
Materialized views can be refreshed either on demand or at regular time intervals. Alternatively, materialized views in the same database as their master tables can be refreshed whenever a transaction commits its changes to the master tables.
Materialized View Logs
A materialized view log is a schema object that records changes to a master table's data so that a materialized view defined on the master table can be refreshed incrementally.
Each materialized view log is associated with a single master table. The materialized view log resides in the same database and schema as its master table.
Materialized views can be refreshed either on demand or at regular time intervals. Alternatively, materialized views in the same database as their master tables can be refreshed whenever a transaction commits its changes to the master tables.
Materialized View Logs
A materialized view log is a schema object that records changes to a master table's data so that a materialized view defined on the master table can be refreshed incrementally.
Each materialized view log is associated with a single master table. The materialized view log resides in the same database and schema as its master table.
CREATE MATERIALIZED VIEW V1 REFRESH FAST FOR UPDATES AS
SELECT * FROM TAB;
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