Simultaneous Installations 7.4 9.x

On mån, 2012-05-07 at 11:08 -0400, Randy Johnson wrote:

Hello,

I have a redhat E5 installation with PostgreSQL 7.4 installation. I have
been tasked with upgrading it to 9.x

I have read that I can install both versions at the same time via YUM and
edit the config file on the new installation to use a different port until
go live time.

Can anyone confirm if this is true?

That would be a good way to go about it, if your packaging supports
parallel installations like this. Judging from the age of your existing
installation (7.4), however, I'd guess that it does not. So you
probably need to build one of the versions from source, do a partial
upgrade, or remove the old version. You will likely have some thinking
to do.

I also read this is the ideal way to go so I can use the newer version of
pg_dumpall to transfer the data because the newer version contains bug
fixes and other efficiencies.

Yes, it's best (or in some cases required) to use the newest pg_dumpall.