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How do I add a column to a materialized view?
You can’t add columns to an MV. You need to drop and recreate it. Or create a new one alongside and switch to that. You will lose any changes to T between you “dropping” the MV and re-creating it.
What are all the privileges required to create the materialized view as creator when the creator owns the materialized view?
Creator Is Owner CREATE MATERIALIZED VIEW or CREATE ANY MATERIALIZED VIEW . CREATE TABLE or CREATE ANY TABLE . READ or SELECT object privilege on the master and the master’s materialized view log or either READ ANY TABLE or SELECT ANY TABLE system privilege.
How can materialized view create primary key?
SQL> alter table t1 add primary key (id); Table altered. SQL> alter table t2 add primary key (id); Table altered. SQL> CREATE MATERIALIZED VIEW MyMV REFRESH COMPLETE ON DEMAND AS SELECT t1. * FROM t1, t2 where t1.id=t2.id; 2 3 4 5 Materialized view created.
How do I create a materialized view?
Use the CREATE MATERIALIZED VIEW statement to create a materialized view. A materialized view is a database object that contains the results of a query. The FROM clause of the query can name tables, views, and other materialized views.
How to get list of columns in a materialized view?
In our db, I see that the definition of the MV matches the columns of the table. select * from all_tab_columns c where c.TABLE_NAME = ‘X’ order by C.COLUMN_ID; I get a SINGLE list of columns.
What are the results of a materialized view?
Query results contain a small number of rows and/or columns relative to the base table (the table on which the view is defined). Analysis of semi-structured data. Aggregates that take a long time to calculate.
How are materialized views used in query optimizer?
The query optimizer can automatically rewrite queries against the base table or regular views to use the materialized view instead. For example, suppose that a materialized view contains all of the rows and columns that are needed by a query against a base table.
How to create a materialized table in SQL?
Dropping the old MV first: SQL> drop materialized view lf; Materialized view dropped. Create a table which will be used as a “target” of the materialized view’s query; it’ll hold data: SQL> create table lf as select * From dept where 1 = 2; Table created.