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DDL Parameters

原创 Linux操作系统 作者:chncaesar 时间:2013-09-25 11:18:07 0 删除 编辑
Enable --> Incoming data
Validate --> Existing data
Rely --> For query rewrite. Specify RELY to activate an existing constraint in NOVALIDATE mode for query rewrite in an unenforced query rewrite integrity mode.
Defer:
1. Defers constraint check to the end of the transaction. This is helpful in cases where parent-child records are to be inserted into tables with FK enabled. 
2. Defers segment creation.
3. Materialized View Build Deferred: The MV is not available for query rewrite until the first complete refresh. Hence, the first complete refresh populates the MV. On the other hand, a build-immediate MV implicitly includes a complete refresh upon creation.

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