Changeset 6682

Timestamp:

05/06/07 05:01:31 (2 years ago)

Author:

marcel

Message:

Provide brief introduction to what optimistic locking is. Closes #8097. [fearoffish]

Files:

• trunk/activerecord/CHANGELOG (modified) (1 diff)
• trunk/activerecord/lib/active_record/locking/optimistic.rb (modified) (1 diff)

trunk/activerecord/CHANGELOG

@@ -1 +1 @@
-*SVN*
+
+* Provide brief introduction to what optimistic locking is. [fearoffish]
-
-* Add documentation for :encoding option to mysql adapter. [marclove]

trunk/activerecord/lib/active_record/locking/optimistic.rb

@@ -1 +1 @@
-module ActiveRecord
-  module Locking
+    # == What is Optimistic Locking
+    #
+    # Optimistic locking allows multiple users to access the same record for edits, and assumes a minimum of 
+    # conflicts with the data.  It does this by checking whether another process has made changes to a record since
+    # it was opened, an ActiveRecord::StaleObjectError is thrown if that has occurred and the update is ignored.
+    #
+    # Check out ActiveRecord::Locking::Pessimistic for an alternative.
+    #
+    # == Usage
+    #
-    # Active Records support optimistic locking if the field <tt>lock_version</tt> is present.  Each update to the
-    # record increments the lock_version column and the locking facilities ensure that records instantiated twice