postgreSQL and history of relational databases

Hi there,

while learning inkscape I did a sketch of picture describing
history of relational databases. It's available from
http://mira.sai.msu.su/~megera/pgsql/

I'd be very grateful for any corrections and comments.
It could be used in PostgreSQL related presentations,
source file is available 
http://www.sai.msu.su/~megera/postgres/history/rel-db-hist.svg
    Regards,        Oleg
_____________________________________________________________
Oleg Bartunov, sci.researcher, hostmaster of AstroNet,
Sternberg Astronomical Institute, Moscow University (Russia)
Internet: oleg@sai.msu.su, http://www.sai.msu.su/~megera/
phone: +007(095)939-16-83, +007(095)939-23-83