Oracle show materialized views

Materialized Views in Oracle. Using materialized views against remote tables is the simplest way to achieve replication of data between sites. If there is a conflict between an updatable materialized view and a master, then, during a refresh, the conflict may result in an entry in the updatable materialized view log that is not in the materialized view log at the master site or master materialized view site. In this case, Oracle uses the updatable materialized view log to remove or. Oracle Database uses these objects to maintain the materialized views in SQL data.

You must have the privileges necessary to create these objects. MVs are used in data-warehouse like aggregate materialized views , materialized views with joins etc. In data warehouses, materialized views are used to precompute and store aggregated data such as sums and averages. Oracle materialized views are one of the single most important SQL tuning tools and they are a true silver bullet, allowing you to pre-join complex views and pre-compute summaries for super-fast response time. If you anticipate performing insert, update or delete operations on tables referenced by a materialized view concurrently with the refresh of that materialized view , and that materialized view includes joins and aggregation, Oracle recommends you use ON COMMIT fast refresh rather than ON DEMAND fast refresh.

Actually ALL_MVIEWS and ALL_ SNAPHOTS displays only the views the user has granted access on. To see all views in a database you must query DBA_MVIEWS or DBA_SNAPHOTS. You need special privileges or roles to query this view like the system privilege SELECT ANY DICTIONARY or the role SELECT_CATALOG_ROLE. Get a list of materialized view log.

A materialized view in Oracle is a database object that contains the of a query. A) all materialized views , with their definition, accessible to the current user in Oracle database (B) all materialized views , with their definition, in Oracle database Query was executed under the Oracle9i Database version. Technically, the materialized view is created as a copy of the source table which could be updated periodically with the changes done on the source table.

It stores data physically and get updated periodically. For local materialized views , it chooses the refresh method which is estimated by optimizer to be most efficient. The refresh methods considered are log-based FAST and FAST_PCT.

FAST_PCT: P: Refreshes by recomputing the rows in the materialized view affected by changed partitions in the detail tables. Attempts a fast refresh. Both tables have materialized view logs and the view meets the criteria for a fast refresh.

However, simply adding one new record to the ATTRIBUTE base table takes several minutes to commit. Yet, once the MV is refreshe it shows as a fast refresh. Iam trying to refresh the materialized view by using: DBMS_MVIEW. Answer: Yes, dbms_metadata.

DDL for materialized views , but it needs formatting. The landmark book Advanced Oracle SQL Tuning The Definitive Reference is filled with valuable information on Oracle SQL Tuning. Force Fast refreshes are only available if Oracle can match rows in the MV directly to rows in the base tables. Complete refreshes completely re-create the MV.

A MV must be refreshed when the data in the underlying tables is changed. Stale means that using the materialized view would yield a different result than using the base table. You can fix this by: Manually refreshing the view. This is useful when data is written periodically (loaded once an hour). They are local copies of data located remotely, or are used to create summary tables based on aggregations of a table’s data.

It utilizes partitioning and dependencies between the objects to minimize the time it takes to refresh and maintain the data as close to the underlying tables as possible. Database designers can use materialized views to prejoin tables, presort solution sets, and presummarize complex data warehouse information. Because this work is completed in advance, it gives end users the illusion of instantaneous response time.

Therefore, whenever a transaction commits which has updated the tables on which a materialized view is define those changes are automatically reflected in the materialized view. In the Oracle database server use, another user (called MIMIC2DEVEL) created a materialized view and made it public. How to view the original script that was used to built it?