Can we drop materialized view?
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Can we drop materialized view?
Use the DROP MATERIALIZED VIEW statement to remove an existing materialized view from the database. When you drop a materialized view, Oracle Database does not place it in the recycle bin. Therefore, you cannot subsequently either purge or undrop the materialized view.
How do I drop materialized view log?
To drop a materialized view log, you must have the privileges needed to drop a table. Specify the schema containing the materialized view log and its master table. If you omit schema , then Oracle Database assumes the materialized view log and master table are in your own schema.
How do I drop a materialized view in hive?
Drop a materialized view before performing a DROP TABLE operation on a related table. Hive does not support dropping a table that has a relationship with a materialized view. In this task, you drop a materialized view named mv1 from the my_database database. Drop a materialized view in my_database named mv1 .
How do I drop a materialized view in Oracle 12c?
How do I give a view a privilege in Oracle?
To create a view in your own schema, you must have the CREATE VIEW system privilege. To create a view in another user’s schema, you must have the CREATE ANY VIEW system privilege. To create a subview, you must have the UNDER ANY VIEW system privilege or the UNDER object privilege on the superview.
How do I drop a view in Oracle?
To remove a view from the database, you use the following DROP VIEW statement:
- DROP VIEW schema_name.view_name [CASCADE CONSTRAINT];
- CREATE VIEW salesman AS SELECT * FROM employees WHERE job_title = ‘Sales Representative’;
- SELECT * FROM salesman;
How do I create a log for materialized view?
CREATE MATERIALIZED VIEW LOG
- Use the CREATE MATERIALIZED VIEW LOG statement to create a materialized view log, which is a table associated with the master table of a materialized view.
- create_materialized_vw_log::=
- logging_clause::=
- new_values_clause::=
- schema.
- table.
What is query rewrite in materialized view?
Overview of Query Rewrite. One of the major benefits of creating and maintaining materialized views is the ability to take advantage of query rewrite, which transforms a SQL statement expressed in terms of tables or views into a statement accessing one or more materialized views that are defined on the detail tables.
What is DBMS_MVIEW refresh?
Refreshing materialized views To refresh the Oracle materialized view, call one of the procedures in DBMS_MVIEW. The DBMS_MVIEW package provides three types of refresh operations: DBMS_MVIEW. REFRESH: Refreshes one or more Oracle materialized views.
How do I drop a view?
The syntax for the SQL DROP VIEW Statement is: DROP VIEW view_name; view_name. The name of the view that you wish to drop.
How do you remove a view?
Right-click the view you want to delete and click Delete. In the Delete Object dialog box, click OK.
Why materialized view log is created?
Oracle Database can use this materialized view log to perform fast refreshes for all fast-refreshable materialized views based on the master table. To fast refresh a materialized join view, you must create a materialized view log for each of the tables referenced by the materialized view.
Why do we need materialized view log?
The Oracle database uses the materialized view log to refresh materialized views based on the master table. This process is called fast refresh and improves performance in the source database.
