silverstripe/sapphire — pull request #729 by hafriedlander (2012-08-21 03:53:36+00:00)
Title: FIX Hierarchy#liveChildren couldnt handle lots of pages

Hierarchy#liveChildren was generating a list of all IDs of all pages
on staging. When a site had lots of pages, this basically killed the
tree.

Fix by adding new versioned mode, stage_unique, which uses a
subselect to only return items from a stage that are in no
other stage.