Re: DDL & long-running query

From: Mladen Gogala <gogala_at_sbcglobal.net>
Date: Thu, 12 May 2005 04:00:13 GMT
Message-ID: <pan.2005.05.12.04.00.13.473233@sbcglobal.net>

On Wed, 11 May 2005 03:50:12 -0700, tim.kearsley wrote:

> I don't believe this is correct. The OP mentioned a long-running
> QUERY. Surely a query holds no locks and the ALTER TABLE command would
> therefore complete without any problem?

Query holds so called "shared parse lock" which will prevent any DDL statement from obtaining the necessary exclusive dictionary lock neeed for changing its structure. You can take a peek at V$LOCK and look for yourself. Your ALTER TABLE command would wait until query finishes.

-- 
Demagogue: One who preaches a doctrine he knows to be untrue to 
           men he knows to be idiots. 
H.L. Mencken

Received on Wed May 11 2005 - 23:00:13 CDT