Multiple versions on same box

Hello,

For upgrade purposes I now have 7.4 and 8.2 on the same Ubuntu box,
and that brings up some questions that I know of, and I'm sure many
that I haven't thought of yet.

I assume that I'll have to put the full path to the version of psql,
etc, corresponding to the same version database that I want to access.

What is the best way to upgrade? Use pg_dumpall (using 8.2's
program), afterwards redirect that file into v8.2 via psql v8.2?

Many thanks!
Ralph Smith
smithrn(at)u(dot)washington(dot)edu
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