Oracle CREATE INDEX Online

1.1     CREATE index

1. If the target table has DML operation, and no commit, error creating index at this time

Ora-00054:resource busy and acquire with NOWAIT Specifiedor timeout expired;

1. If an index is being created on the target table (CREATE index), the DML operation is blocked;

Summary: The direct CREATE index must determine that the target table has no DML operations, or that indexing is stopped in the business situation.

1.2     CREATE INDEX Online

1. If the target table has DML operation, and does not commit, this time using online will wait for the submission before indexing;

2. if the index is being indexed on the target table (CREATE index online), then the DML operation will not be blocked, but if it is not committed, the index is blocked until the DML Continue to create the index after submission;

Summary: If the target library is being frequently put into storage, consider using online setup.

In fact, along with the contention of resources, is the creation of lock, interested friends can study lock compatibility matrix.

This article is from the "90SirDB" blog, be sure to keep this source http://90sirdb.blog.51cto.com/8713279/1916140

Oracle CREATE INDEX Online