db-derby-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Dag H. Wanvik" <Dag.Wan...@Sun.COM>
Subject Re: Select records that are not locked?
Date Mon, 09 Jan 2006 10:59:14 GMT

Hi,

>>>>> "Mike" == Mike Matrigali <mikem_app@sbcglobal.net> wrote:
Mike> 
Mike> Derby does not support that.  I have heard it referred to as "read past"
Mike> locking.  I don't believe there is any SQL standard or JDBC standard
Mike> description of such a mode.
Mike> 
Mike> It tends to be useful for queue management applications where the app 
Mike> just wants a set of rows to work on and it is ok to skip those that 
Mike> someone else is looking at.  Do you know of any DB's that currently
Mike> support such a feature?

>From a quick google search, it seems that both Sybase and SQL Server
have this feature, although to differing degrees, cf.

http://manuals.sybase.com/onlinebooks/group-as/asg1250e/sqlug/@Generic__BookTextView/55770;pt=55452
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/acdata/ac_8_con_7a_1hf7.asp

Dag

Mike> 
Mike> 
Mike> 
Mike> Danny wrote:
Mike> > Is there a way on a select statement to select all rows that match the where
Mike> > clause criteria, except for any rows that are locked?
Mike> > 
Mike> > Danny Gallagher
Mike> > The Gainer Group
Mike> > 6525 The Corners Parkway
Mike> > Suite 215
Mike> > Norcross Ga, 30092
Mike> >  
Mike> >  
Mike> > 
Mike> > 
Mike> > 
Mike> > 
Mike> > 
Mike> 
-- 
Dag H. Wanvik
Sun Microsystems, Database Technology Group (DBTG)
Haakon VII gt. 7b, N-7485 Trondheim, Norway
Tel: x43496/+47 73842196, Fax:  +47 73842101

Mime
View raw message