francis,
i've had no problems running the latest postgresql (7.3.4) and I think it is now the supported version for oacs.
1. make sure postgres is not already installed on your system. assuming it isn't...
2. try installing a postgres rpm.
3. if you really want to compile, post your error logs. for readline errors specifically, i think you can use the command:
% configure --without-readline
what distribution of linux / version?
in the meantime, the postgresql installation docs on openacs are good, but you might also want to check postgresql.org as they will be a bit more detailed. many times you can find that your question has already been answered by searching the forums here on openacs.org with your error message.
