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创建materialized view

原创 Linux操作系统 作者:learninfly 时间:2009-07-23 13:38:12 0 删除 编辑

create materialized view log on aa;

create materialized view aa on prebuilt table with reduced precision refresh fast with primary key for update as select * from user.aa@dblink;

1.materialized view log

materialized view log只有在fast refresh的时候需要创建。fast refresh是利用materialized view log中的信息来实现增量改变。

2.on prebuilt table

当你删除一个创建在prebuilt table上面的物化视图时,那个prebuilt表仍然存在,仅仅物化视图被删除。

3.with reduced precision

If the materialized view was registered as PREBUILT, the precision of the columns must agree with the precision of the corresponding SELECT expressions unless overridden by the WITH REDUCED PRECISION clause.

The contents of the table must reflect the materialization of the defining query at the time you register it as a materialized view, and each column in the defining query must correspond to a column in the table that has a matching datatype. However, you can specify WITH REDUCED PRECISION to allow the precision of columns in the defining query to be different from that of the table columns.

 

来自 “ ITPUB博客 ” ,链接:http://blog.itpub.net/10322123/viewspace-610032/,如需转载,请注明出处,否则将追究法律责任。

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