Re: Implicit row locking during an UPDATE - Mailing list pgsql-general

From Eric G. Miller
Subject Re: Implicit row locking during an UPDATE
Date
Msg-id 20010524212543.A5353@calico.local
Whole thread Raw
In response to Implicit row locking during an UPDATE  ("Dr. Evil" <drevil@sidereal.kz>)
List pgsql-general
On Fri, May 25, 2001 at 02:23:50AM -0000, Dr. Evil wrote:
>
> I'm still not understanding this, and it's vitally important to the
> project I'm working on, so I have a question:
>
> >From my understanding, this:
>
> UPDATE account SET value = 10 WHERE number = 99;
>
> actually implies all of this:
>
> BEGIN;
> SELECT value FOR UPDATE FROM account WHERE number = 99;
> UPDATE account SET value = 10 WHERE number = 99;
> COMMIT;
> END;
>
> Is this correct?  If so, there's something I don't understand.

No.  Maybe you want to read the manual.  Specifically look at
transaction isolation level under MVCC.  Hmm, SET TRANSACTION ISOLATION
LEVEL doesn't seem to be taking in 7.1.1... Is that a bug?  Guess the
only way to be sure is to use the transaction semantics above...

--
Eric G. Miller <egm2@jps.net>

pgsql-general by date:

Previous
From: Lincoln Yeoh
Date:
Subject: Re: Pg - Perl 5 prob
Next
From: Ludwig Meyerhoff
Date:
Subject: Re: Re: Pg - Perl 5 prob