What happens to materialized view if table is dropped?

What happens to materialized view if table is dropped?

If you drop a materialized view, then any compiled requests that were rewritten to use the materialized view will be invalidated and recompiled automatically. If the materialized view was prebuilt on a table, then the table is not dropped, but it can no longer be maintained by the materialized view refresh mechanism.

How do I delete a materialized view in Oracle?

For you to delete rows from a table, the table must be in your own schema or you must have the DELETE object privilege on the table. For you to delete rows from an updatable materialized view, the materialized view must be in your own schema or you must have the DELETE object privilege on the materialized view.

How do you drop a table if it exists in Oracle?

DROP TABLE IF EXISTS `table_name`; This way, if the table doesn’t exist, the DROP doesn’t produce an error, and the script can continue. SELECT * FROM dba_tables where table_name = ‘table_name’; but the syntax for tying that together with a DROP is escaping me.

How do I delete an Mview?

To Delete a Saved Viewport Arrangement

1. Click View tab Viewports panel Named. Find.
2. In the Viewports dialog box, Named Viewports tab, select the name of the viewport configuration you want to delete.
3. Press the DELETE key.

What will happen if a view is dropped?

Remarks. When you drop a view, the definition of the view and other information about the view is deleted from the system catalog. All permissions for the view are also deleted. Any view on a table that is dropped by using DROP TABLE must be dropped explicitly by using DROP VIEW.

Can you truncate a materialized view?

As such, we do not generally recommend truncating a materialized view. Although each query on the view will still show up-to-date results, the query might run more slowly as Snowflake updates the materialized view or looks up data in the base table.

How do you check if data exists in a table in Oracle?

select decode(count(*), 0, ‘N’, ‘Y’) rec_exists from (select ‘X’ from dual where exists (select ‘X’ from sales where sales_type = ‘Accessories’));

How do I recover a dropped table in Oracle without flashback?

Create a New Table

1. Invoke SQL*Plus and connect as the SYSTEM user.
2. Alter session to pluggable database container orclpdb. # SQL> alter session set container=orclpdb; Session altered.
3. Create a new table named HR. REGIONS_HIST .
4. Query the new HR. REGIONS_HIST table.

Does the SQL view exists if the table is dropped from the database?

Answer: Yes, in Oracle, the SQL VIEW continues to exist even after one of the tables (that the SQL VIEW is based on) is dropped from the database. However, if you try to query the SQL VIEW after the table has been dropped, you will receive a message indicating that the SQL VIEW has errors.

Can we alter view in Oracle?

2 Answers. ALTER VIEW is not used in this way. The only options for altering a view are to add/drop/modify constraints or to RECOMPILE the view. If you want to add columns then just run the CREATE OR REPLACE VIEW statement again with a different select.

Purpose. 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.

What happens if I drop a materialized view?

If you drop a materialized view, then any compiled requests that were rewritten to use the materialized view will be invalidated and recompiled automatically. If the materialized view was prebuilt on a table, then the table is not dropped, but it can no longer be maintained by the materialized view refresh mechanism.

How to drop table if exists in Oracle?

There is no ‘DROP TABLE IF EXISTS’ in oracle, you would have to do the select statement. try this (i’m not up on oracle syntax, so if my variables are ify, please forgive me): Show activity on this post. This function verifies that the input parameter string is a qualified SQL identifier of an existing SQL object. Show activity on this post.

How to create a materialized view in a schema?

The materialized view must be in your own schema or you must have the DROP ANY MATERIALIZED VIEW system privilege. You must also have the privileges to drop the internal table, views, and index that the database uses to maintain the materialized view data. Specify the schema containing the materialized view.