Oracle FAQ Your Portal to the Oracle Knowledge Grid
HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US
 

Home -> Community -> Usenet -> comp.databases.theory -> Re: Theoretical Basis for SELECT FOR UPDATE

Re: Theoretical Basis for SELECT FOR UPDATE

From: vc <boston103_at_hotmail.com>
Date: 30 Sep 2005 14:44:09 -0700
Message-ID: <1128116649.741537.52460@o13g2000cwo.googlegroups.com>

David Cressey wrote:
[...]
> By SELECT FOR UPDATE, you take out the higher level lock earlier. This
> reduces concurrency, but also reduces deadlocks.
>

SELECT FOR UPDATE is not useful for locking databases and is not implemented there. It's only reason to be, as wrote before, is to emulate repeatable reads in a multiversioning database.

Besides, select for update can create deadlocks as easily as a run-of-the mill update or delete. Received on Fri Sep 30 2005 - 16:44:09 CDT

Original text of this message

HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US