Why not just dump relational?

> Post-relational and MultiValue are synonymous. But no, it doesn't mean
> "multiple values per row", it means "multiple values per CELL".

My bad. I was talking about this thing, with postgres's Array types.

http://www.postgresql.org/docs/8.0/interactive/arrays.html

So, now we have established postgres as either pre- or post-relational, or possibly both...
;-)

Your talk about the query optimizer's unworthiness is unconvincing to me. Not all projections
are about fetching a single entity. Some queries are about fetching aggregates such as
statistics of all the rows in the database. It is not useless to have these queries run well,
too.

It would seem advantegous to be able to restrict the amount of data fetched about an entity to
the absolute minimum. For instance, in many databases you can build an internally maintained
"clone" of a table by indexing a set of its columns. When a query concerning that table
requesting only those columns is executed, chances are that the optimizer chooses to read the
data from the index instead of the table proper.