We should be prepared to materialize a hidden partition, before using it.
We should be prepared to materialize a hidden partition,
before using it.

Not all cases are covered yet, so you may tumble on side-effects.

I have materialized all hidden segments in the iterators, but this
is probably not strictly necessary.

zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb