I try to understand why HeapTupleHeaderData structure has t_datum
member. This is use only on few places and from my point of view this
information should be stored in the HeapTupleData structure or split
HeapTupleHeaderData it into two structures (DatumTupleHeaderData). The
idea behind my question is that I need process different versions of
HeapTupleHeaders for different page layouts and I try to discover how to
deal with the union.
Thanks Zdenek
