commit db52d736470a580e4cf1c17bef550ab6faf42eff
Author: Damien Tournoud <damien@commerceguys.com>
Date:   Wed Jan 18 16:01:41 2012 +0100

    Issue #1369332: Avoid deadlock issues on the {node} table.

diff --git a/core/modules/node/node.install b/core/modules/node/node.install
index 82fd2e7..ce50d85 100644
--- a/core/modules/node/node.install
+++ b/core/modules/node/node.install
@@ -18,12 +18,15 @@ function node_schema() {
         'unsigned' => TRUE,
         'not null' => TRUE,
       ),
+      // Defaults to NULL in order to avoid a brief period of potential
+      // deadlocks on the index.
+      // @see http://drupal.org/node/1369332
       'vid' => array(
         'description' => 'The current {node_revision}.vid version identifier.',
         'type' => 'int',
         'unsigned' => TRUE,
-        'not null' => TRUE,
-        'default' => 0,
+        'not null' => FALSE,
+        'default' => NULL,
       ),
       'type' => array(
         'description' => 'The {node_type}.type of this node.',