Oracle base materialized view

How do you create an oracle view? When to use materialized view? Can we use create or replace materialized view? How to refresh of materialized view? Materialized Views in Oracle.

Using materialized views against remote tables is the simplest way to achieve replication of data between sites. The complication comes from the lag between the last refresh of the materialized view and subsequent DML changes to the base. You can create a nested materialized view on materialized views , but all parent and base materialized views must contain joins or aggregates.

If the defining queries for a materialized view do not contain joins or aggregates, it cannot be nested. Home Articles 19c Here. Oracle 18c introduced the ability to use the ON STATEMENT refreshes of materialized views built with JSON_TABLE function calls.

Oracle Database uses these objects to maintain the materialized view data. 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 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. By default, the database collects and stores basic statistics about materialized view refresh operations for the entire database. This process is called a complete refresh. Usually, a fast refresh takes less time than a complete refresh.

You define the view and Oracle creates the base table underneath it automatically. By executing the view and placing the resulting data in the base table you gain performance. A materialized views log is located in the master database in the same schema as the master table. They are useful for a variety of reasons.

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. So, for example, if you have a bunch of existing reports against a detail table that produce daily, monthly, and yearly aggregate , you can create a materialized view on the base table that aggregates the data at a daily level and the optimizer can utilize that materialized view for all your existing queries. WHEN MATERIALIZED VIEW REFRESH, ALL RECORDS IN THE VIEW WILL BE AFFECTED OR ONLY CHANGED RECORDS WILL GET AFFECTED.

You must also have access to any master tables of the. If you do a complete refresh then the MV is rebuild. HOW MVIEW LOOK FOR THE BASE TABLE WHEN REFRESHING.

I am using Oracle9i and creating a materialized view log for base table for fast refresh. COM YES NO ROWID 1ORACLE MATERIALIZED VIEW select count. It stores data physically and get updated periodically. This means that any user or application that needs to get this data can just query the materialized view itself, as though all of the data is in the one table, rather than running the expensive query that uses joins, functions, or subqueries.

Mike Ault Burleson Consulting. One of the suggested architectures to allow for rapid reporting without stressing the base tables is to use partitione refresh on commit, materialized views. Some materialized views have status invali however, they compile with no errors. I want to get a list of materialized view logs in Oracle.

A view uses a query to pull data from the underlying tables. Iam trying to refresh the materialized view by using: DBMS_MVIEW. Then I have created a stored procedure like this: CR.