Re: upgrade question: running different versions on one host

Ben Kim <bkim@edsun.coe.tamu.edu> writes:
> I compiled 7.3.4 on a host already running 7.2.1, with
> "--prefix=/different/directory --pgport=5833 ..." option.

> According to the installation instructions on
> developer.postgresql.org/docs/postgres/install-procedure.html, I thought I
> only have to give a different directory as the --prefix, then
> --exec-prefix, --bindir, --datadir, etc. will automatically be made
> different.

> But surprisingly, when I did "make install", the postgres 7.2.1's
> "postgres" and "ecpg" binary was overwritten.

What were the paths in question, exactly?  I do this constantly (I have
four or five different versions of PG on my devel machines) and I've
never had a problem.

> I intentionally used the same user name for both versions, only used a
> different directory. The two installations share the same PGDATA
> environment variable.

You *can't* have two installations share a PGDATA directory.  The newer
version should have refused to start because $PGDATA/PG_VERSION would
have looked wrong to it.

            regards, tom lane