In NXQL when testing ecm:isCheckedInVersion = 0 we generate:
... LEFT JOIN versions ON h.id = versions.id ... WHERE ...versions.id IS NULL
This is costly and since NXP-5797 can be improved using the new hierarchy.isversion boolean.
VCS: allow NXQL to query complex properties
Add versioning-related features to Nuxeo Core to support the CMIS versioning model