Methods and apparatus are described for splitting a page (or node) in an index tree database index for a multi-master database. The methods include creating a first split page of a first page. The first page belongs to a first set of pages and comprises a hinge page. The hinge page also belongs to a second set of pages. Updating the first set of pages may cause the hinge page itself to split, creating a split of the hinge page. The second set of pages is updated in response to creating the split of the hinge page. Described are techniques whereby the updates to the first and second sets of pages are atomic, that is, they all succeed or they all fail, which may realize any of several benefits.