The advantage of creating this type of materialized view is that expensive joins will be precalculated. If a materialized view fails during refresh at COMMIT time, you must explicitly invoke the refresh procedure using the DBMS_MVIEW package after addressing the errors specified in the trace files. Are you refreshing Materialized view (Complete/Fast…) or static ? If a materialized view contains joins and aggregates, then it cannot be fast refreshed using a materialized view log. You can automatically refresh intermediate materialized views in a nested hierarchy using the nested = TRUE parameter, as described in "Nesting Materialized Views with Joins and Aggregates". As a result, there is no difference in the manner in which Oracle Database detects the various types of materialized views (for example, materialized join views with no aggregates). When disabled, query rewrite cannot be supported if this materialized view is in partial stale state with regard to the table named in the RELATED_TEXT column. If a capability is not possible for more than one reason, a row is displayed for each reason. Fast refreshes allow you to run refreshes more often, and in some cases you can make use of refreshes triggered on commit of changes to the base tables, but this can represent a significant overhe… A query can reference both local and remote tables. Here are some examples of materialized views with aggregates. You could have compressed this table to save space. Therefore this method may not be suitable if many users are concurrently changing the tables upon which the materialized view is based. Fact tables include facts (also called measures) such as sales, units, and inventory. The use of summary management features imposes no schema restrictions, and can enable some existing DSS database applications to improve performance without the need to redesign the database or the application. See Oracle Database SQL Language Reference for further details. Mechanisms to define materialized views and dimensions. You need to know your update window for the following activities: Updating or rebuilding the indexes on the detail data, Performing quality assurance tests on the data, Updating the indexes on the materialized views. If this capability is not possible, no form of fast refresh from a materialized view log is possible. Table 8-2 Requirements for Materialized Views with Aggregates. Explain an existing or potential materialized view with output to MV_CAPABILITIES_TABLE: Explain an existing or potential materialized view with output to a VARRAY: One of the simplest ways to use DBMS_MVIEW.EXPLAIN_MVIEW is with the MV_CAPABILITIES_TABLE, which has the following structure: You can use the utlxmv.sql script found in the admin directory to create MV_CAPABILITIES_TABLE. Materialized views are also useful in remote data marts. Â This document was written initially for version 9, and has been updated through 11gR2.Â. The name of a materialized view must conform to standard Oracle naming conventions. When using query rewrite, create materialized views that satisfy the largest number of queries. Alternatively, if the previous example did not include the columns times_rid and customers_rid, and if the refresh method was REFRESH FORCE, then this materialized view would be fast refreshable only if the sales table was updated but not if the tables times or customers were updated. If you use DBMS_MVIEW.REFRESH, the entire materialized view chain is refreshed and the coverage starting from the specified materialized view in top-down fashion. A materialized view log (snapshot log) is a schema object that records changes to a master table's data so that a materialized view defined on that master table can be refreshed incrementally. from departament, people where people.dep_Id=departament.id; this view refresh 1 time per min, but when someone insert new data in tables view refresh stopped. Required though user tables added to the table named in the SELECT clause benefits of materialized views,,. Which shows you how to use fast refresh capabilities is in table 8-3 incomplete time... 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