At least one read operation of at least one object of a data container is initiated. The data container includes an anchor object, a first internal data object and a first garbage collection object, the anchor object comprising a pointer to a versioned structure tree. Thereafter, in response to the at least one incompatible write operation, a second internal data object and a second garbage collection object are created for the data container. The second garbage collection object has a reference to the second internal data object. Subsequently, the second internal data object is installed in the anchor object and the first garbage collection object is passed to a garbage collection process so that space used by the first garbage collection object in a database can be reused. Related apparatus, systems, techniques and articles are also described.