Re: Dirty reads in Oracle 7.2

From: Thomas J Kyte <tkyte_at_us.oracle.com>
Date: 1996/01/03
Message-ID: <4ce6c4$j2o_at_inet-nntp-gw-1.us.oracle.com>#1/1


yogen_at_astro.ocis.temple.edu (Yogen Sanghani) wrote:

>How do I perform "dirty read" in a PL/SQL stored procedure in Oracle 7.2. By
>dirty read I mean that a select should be able to read rows that may be locked
>by any insert/update/delete statements.
 

>Any suggestions appreciated. Thanks.
 

>----
>Yogen.

Oracle does not support "dirty reads", never has. It is not needed in Oracle. A "select * from T" will not block in the data. We use a multi-versioning read consistency model to avoid writers blocking readers and readers blocking writers. You get the right answer (without taking out shared read locks and blocking writers) and you never block.

Check out the server concepts manual, Chapter 10 for more information.

Thomas Kyte
tkyte_at_us.oracle.com
Oracle Government Received on Wed Jan 03 1996 - 00:00:00 CET

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