Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uwm.edu!rutgers!njin!uupsi!cai.com!gupyo01
From: gupyo01@cai.com
Newsgroups: comp.databases
Subject: Re: Predicate Locks
Message-ID: <350.2731ec80@cai.com>
Date: 2 Nov 90 22:00:32 GMT
References: <90Oct18.180225edt.12896@neat.cs.toronto.edu>
Organization: Computer Associates International
Lines: 23

In article <90Oct18.180225edt.12896@neat.cs.toronto.edu>, vinay@ai.toronto.edu ("Vinay K. Chaudhri") writes:
> The idea of using predicate locks for database concurrency control
> has been around for over ten years.  But still there are not many
> commercial systems which use predicate locking as a primary method
> for concurrency control.
> 
> [... stuff deleted ...]
>
> My question is the following:  Are there really no commercial systems
> that use predicate locking ?  Are the reasons for their in-applicability
> as cited above are correct ?  Are predicate locks dead as a research
> or application area ?
> 

At least one commercial product uses predicate locks: CA-DB from
Computer Associates.  One of the reasons for this might be that
the product was originally developed by a start-up which had
Kapali Eswaran as one of its founders.  For more information on this,
please contact me.

Yogesh Gupta
Computer Associates
(408) 922-2633