Hi Djoerd, All document management functions return the docmgt type, as a mechanism to ensure that such queries do not perform any document updates. For MonetDB, this separation is handy, as document management and XQUF updates rely on two different mechanisms (checkpointing vs WAL) and if queries would rely on both, it would be hard to make them atomic. Pathfinder supports the 'declare document management function' syntax extension (imilar to the xQUF notation 'declare updating function') to allow user-defined functions that perform document management. Peter