Re: Lock-free databases
From: Mark D Powell <Mark.Powell_at_eds.com>
Date: 4 Nov 2005 07:37:13 -0800
Message-ID: <1131118633.320763.200400_at_o13g2000cwo.googlegroups.com>
Date: 4 Nov 2005 07:37:13 -0800
Message-ID: <1131118633.320763.200400_at_o13g2000cwo.googlegroups.com>
If there is any mechanism in the db that single thread access to data
such as not allowing two processes to change a data item at the same
time then the db is not "lock" free. The vendor can call the mechanism
latches or enqueues or anything else but the reality is that the
mechanism is a lock.
In fact Oracle uses all three terms. A lock, latch, and an enqueue all
serve the same purpose: single thread access to something. With Oracle
the difference is what that something is, and how the mechanism is
implemented. Unless the db is read only I do not see how a db can be
"lock free". I do not think the claim is honest.
IMHO -- Mark D Powell -- Received on Fri Nov 04 2005 - 16:37:13 CET