libpq.so.2 not found (RedHat 7.3 RPMs)

I had trouble running PHP after upgrading to PSQL 7.3.2 from 7.2.4. I got
the error message

[19-Apr-2003 20:41:22] PHP Warning:  Unable to load dynamic library
'/usr/lib/php4/pgsql.so' - libpq.so.2: cannot open shared object file: No
such file or directory in Unknown on line 0

While the rpm package postgresql-libs said that it installed the
/usr/lib/libpq.so.2.0 file, there was none. But when I made a synlink, it
worked fine.

Peter of the Norse