Dear pgsql-hackers list,
First a few words of introduction : I'm 43 and, while I have been
introduced to computing for a long time (my first exposure was a small
Fortran exercise I wrote in '74 (!) for a timesharing system on an
hardcopy terminal ...), my coding abilities are somewhat rusty. I am
mainly a user by now, no longer a coder, and my interests in computers
is now in making my life simpler (I'm a biostatistician, among other
things).I probably won't be contributing any code to PostgreSQL. Some
bug reports, maybe ...
However, I've lurked on some of the PostgreSQL lists for 2 to 3 months
(through the Web interface), and I feel that I might offer some
advice, based on my past experience of seeing a lot of projects
growing (or dying, due to feeping creaturism(TM) ...).
So I will shamelessly pull my first plea, related to the proposed
change to the default behaviour of PostgreSQL in querying classes with
subclasses.
I *strongly* suggest not to change anything in the default behaviour,
which is what is expected from an SQL-compliant system, even if the
database in question uses inheritance internally.
The reason for that plea is that a modification would crash any
program not explicitly written for inheritance features : such
features might be used by, say, the administrator and coere
programmers of a database, who are not necessarily publish this
internal use of inheritance to end-users. Furthermore, such a change
would forbid evolution of a database from a pure-relational to an
object-orien,ted one : the two representations would be incompatible.
It should also pointed out that most interface programs (such as ODBC
or JDBC drivers) are not and will not in a foreseeable future be
designed for use of these features. Modifying the default behaviour
would break them.
Apart from that, I am, after 17 years of exposure to the concepts of
object-oriented programming, still to be convinced of the value of
this paradigm. This is *not* to suggest that these developments should
be left over ! However, I *feel* that the real issues behind this
concept are not yet fully understood, and that some deep theoretical
work remains to be done (in logic, for example : while the
well-understood relational theory directly relates to set theory, I
think that a mathematically correct objects-and-types theory shoud
emanate from category theory but remains to be created ...).
Your thoughs ?
Emmanuel Charpentier
