Serious performance problem

Hello,

I discussed a problem concerning the speed of PostgreSQL compared to
MS SQL server heavily on postgres-general list.  The thread starts with
message
   http://fts.postgresql.org/db/mw/msg.html?mid=1035557

Now I tried a snapshot of version 7.2 and got an increase of speed of
about factor 2.  But sorry this is really not enough.  The very simple
test I pointed to in my mail is even much to slow and the issue would
probably spoil down the whole project which should be a complete open
source solution and would perhaps and in any M$ stuff.  I´ve got under
heavy preasur from my employer who was talking about the nice world
of MS .net (while he is using MS-SQL exclusively).  To make the thing
clear the issue is the gal database of infectious diseases in Germany
runned by the Robert Koch-Institute.  So the beast could be of some
importance for increasing the acceptance of PostgreSQL and Open Source
in the field of medicine which is generally known for the money which
is involved in.  So I really hope that some skilled programmers would
be able to find a good way to solve the performance issue perhaps by
just profiling the simple query
  SELECT Hauptdaten_Fall.MeldeKategorie, Count(Hauptdaten_Fall.ID) AS Anz FROM Hauptdaten_Fall WHERE
(((Hauptdaten_Fall.IstAktuell)=20))
GROUP BY Hauptdaten_Fall.MeldeKategorie ORDER BY Hauptdaten_Fall.MeldeKategorie;

to the data set I put on
  http://www.foodborne-net.de/~tillea/ifsg/ifsgtest.dump.bz2

If this should take less than half a second on a modern PC I could
continue to try mo realistic queries.

I really hope that I could readjust the image of PostgreSQL in the
eyes of my M$-centered colleagues.

Kind regards
      Andreas.