#lock_nested_set very slow on mysql with thousands of subtasks (#23318).

Patch by Stephane Evr.

git-svn-id: http://svn.redmine.org/redmine/trunk@15891 e93f8b46-1217-0410-a6f0-8f06a7374b81

1 files changed, 4 insertions, 1 deletions

diff --git a/lib/redmine/nested_set/issue_nested_set.rb b/lib/redmine/nested_set/issue_nested_set.rb
index afbe6b995..e939f96b6 100644
--- a/lib/redmine/nested_set/issue_nested_set.rb
+++ b/lib/redmine/nested_set/issue_nested_set.rb
@@ -158,7 +158,10 @@ module Redmine
           self.class.reorder(:id).where(:root_id => sets_to_lock).lock(lock).ids
         else
           sets_to_lock = [id, parent_id].compact
-          self.class.reorder(:id).where("root_id IN (SELECT root_id FROM #{self.class.table_name} WHERE id IN (?))", sets_to_lock).lock.ids
+          self.class.reorder(:id).
+            joins("INNER JOIN #{self.class.table_name} t2 ON #{self.class.table_name}.root_id = t2.root_id").
+            where("t2.id IN (?)", sets_to_lock).
+            lock.ids
         end
       end