how to terminate a process when kill fails

Running PostgreSQL 7.2.1 on RedHat Linux 7.2.

I think I may have asked before, but I never got an answer
that told me one way or another -

How can I kill processes without kill -9 <pid> and
ruining the database?

I've tried restarting postgreSQL hoping that it cleans up
a few things. I've tried to simply kill the processes that
were running. Nothing happens; nothing dies. I don't see
much of anything in the messages / log files.

Any suggestions?

-X