refresh materialized view

, materialized views are referred to as primary tables (during replication) or schedules (in the Data Warehouse).For replication, materialized views allow you to maintain a copy of the remote data locally, which is read-only. If you want to modify the local copy, you must use the Advanced Replication feature. When you want to extract data from a table or view, yo

Tags: force entity fetch number Save time existence comm Simple aggregation/*Oracle materialized View*//*Why use materialized views?Materialized views are widely used as a means of SQL tuning in a data warehouse environment.A large number of long query statements, poor processing, will cause serious I/O problems.*//*Wh

, and Windows users. They can be seen as special mqts. Fullselect is part of the summary table definition. It contains a group by clause that summarizes the data in the table referenced in fullselect. You can regard MQT as a materialized view. Both the view and MQT are defined based on a query. When a view is reference

by clause that summarizes the data in the table referenced in fullselect. You can regard MQT as a materialized view. Both the view and MQT are defined based on a query. When a view is referenced, the view-Based Query runs. However, MQT actually stores the query results as

Materialized views can be refreshed in three ways: complete, fast, and force: (1) A complete refresh operation deletes all records in the table (if a single table is refreshed, truncate may be used ), then, the materialized view is regenerated based on the definition of the query statement in the

referenced in fullselect. You can regard MQT as a materialized view. Both the view and MQT are defined based on a query. When a view is referenced, the view-Based Query runs. However, MQT actually stores the query results as data. You can use the data in MQT instead of the

Create materialized view [view_name]Refresh [Fast|complete|force][On [Commit|demand] |Start with (start_time) next (next_time)]As{Create a query statement for materialized views} These are the common syntax for Oracle to create materialized views (

), COL4 VARCHAR(128), COL5 VARCHAR(128), PRIMARY KEY (ID)) ORGANIZE BY ROW; Create an MQT table CREATE TABLE T_MQT ( ID, COL1, COL2, COL3 ) AS ( select ID, COL1, COL2, COL3 from T ) DATA INITIALLY DEFERRED REFRESH IMMEDIATE MAINTAINED BY SYSTEM;SET INTEGRITY FOR T_MQT IMMEDIATE CHECKED FULL ACCESS; Write Data to the original table insert into T(ID, COL1, COL2, COL3, COL4, COL5) values (1, 'col1', 'col2', 'col3', '

Transferred from: http://blog.csdn.net/joshua_peng1985/article/details/6213593 Introduction Materialized views are a special physical table, and the materialized view is relative to a normal view. Normal view is a virtual table, the application of a large limit, any query on

Label:Original address: http://www.cnblogs.com/Ronger/archive/2012/03/28/2420962.html Materialized views are a special physical table, and the materialized view is relative to the normal view. The normal view is a virtual table, the limitations of the application are large,

), COL3 VARCHAR (128), COL4 VARCHAR (128), COL5 VARCHAR (128), PRIMARY KEY (ID) ORGANIZE by ROW; Create an MQT table CREATE TABLE t_mqt (ID, COL1, COL2, COL3) as (select ID, COL1, COL2, COL3 from T) DATA initially Deferr ED REFRESH IMMEDIATE maintained by SYSTEM; SET INTEGRITY for T_MQT IMMEDIATE CHECKED full ACCESS; Write data to the original table Insert into T (ID, COL1, COL2, COL3, COL4,

On demand: REFRESH is performed only when the materialized view is refreshed. That is, the materialized view is updated to ensure data consistency between the base table and the base table; On commit: Once the base table has a COMMIT, that is, the transaction is committed,

Classification On demand: REFRESH is performed only when the materialized view is refreshed. That is, the materialized view is updated to ensure data consistency between the base table and the base table; On commit: Once the base table has a COMMIT, that is, the transaction

First, Oracle materialized view syntaxCreate materialized view [view_name]Refresh [Fast|complete|force][On [Commit|demand] | Start with (start_time) next (next_time)]As{Create a query statement for materialized views}These are the

table (during replication) or a schedule (in a data warehouse). For replication, materialized views allow you to maintain a copy of remote data locally, which is read-only. If you want to modify the local copy, you must use the Advanced Copy feature. When you want to extract data from a table or view, you can extract it from the materialized

Materialized View, which is used to pre-calculate and save the results of time-consuming operations such as table join or aggregation. In this way, these time-consuming operations can be avoided during query execution, and get results quickly. Materialized views are similar to indexes in many aspects: materialized view

Oracle materialized view log structure To refresh a materialized view quickly, you must create a materialized view log. This article briefly describes the meaning and usage of each fiel

. This is evidenced by the query results of user_segment; Parameters related to materialized views: COMPATIBLE must be later than 8.1.0 QUERY_REWRITE_ENABLED = TRUE enable query rewriting (default QUERY_REWRITE_INTEGRITY = ENFORCED-only restrictions and rules ENFORCED and guaranteed by Oracle are used for query (default ); TRUSTED-in addition to Oracle's mandatory and guaranteed constraints and rules, the query can also be rewritten using any relatio

Materialized views are a special physical table, and the materialized view is relative to the normal view. The normal view is a virtual table, the limitations of the application are large, any query on the view, Oracle is actually

A materialized view is a database object that contains a query result. It is a local copy of remote data or is used to generate a summary table based on the sum of data tables. Materialized View stores data based on remote tables, also known as snapshots. Materialized vi