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In different situations, end users are forced to run queries that summarize large amounts of data and calculation of some values on the basis of such statements. Usually such queries are common in databases that support applications such as SSD. Sometimes, however, although the consultation database running OLTP to see these ugly, adversely affecting regular OLTP performance. Oracle launches a new feature called materialized views when the required data can be stored in a pre-summary mode, which allows direct access to applications and use them without having to make real-time ad-hoc, a summary of data. The summarized result sets are available for single file recovery, as with the recovery of a normal table. Materialized views to work on the concept of summarizing the data once and use it many times, saving repetitive data aggregations by end users. Materialized views are schema objects such as tables, indexes that allow data to a base table that is maintained in a different way within the same database or file. Same or different within a Snapshots used for another drop database replication in this broad category, too. Materialized views in the form of snapshots are preserved only for the replication of data between distributed databases. However, an important reason for the introduction of materialized views in the physical design is to allow applications access to summary data. However, a detailed analysis is necessary before creating a materialized view to determine the database tables and columns required to include in the view, what type of summary and aggregation in general do not meet the data users, and the best way to present them in a format ready for use. Materialized views are quite similar to the concept of indexes, since it must be maintained as a database to change tables (which can cause overhead during DML on base tables). Materialized views to avoid delaying the loading of bulk data, base tables; you can drop / disable them before loading, and re-create or re-enable them after loading. Moreover, they tend to consume space. This mode of consumption may have a significant impact if the views are built on large tables, but they save a great amount of work accordingly. Materialized views can be fully updated every time, or an incremental basis. View current register is similar to the concept of a snapshot log, Oracle is used to gradually upgrade. Materialized views employ table within. To cope with this table, just like any other table. In other words, you can create an index on it, you can partition, and so on. VIES demand a cost-based optimizer CBO. Materialized views can be used directly or indirectly to end users, which can directly question the point of view, if they are aware of their existence. If there is a demand and users have long been accustomed to using the base tables directly, do not need to be retrained in any way. They can continue to base tables of queries and automatically write the CBO queries using materialized views, when possible or appropriate. Gitesh Trivedi has 14+ years of experience and author of technical writing of Support For Oracle and also author of Oracle DBA Interview Questions with answers books.
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