Re: Upgrade from 9.5.4 to 9.6.1

On Tue, 15 Nov 2016, Rich Shepard wrote:

> $ /usr/bin/pg_ctl --version
> pg_ctl (PostgreSQL) 9.6.1
>
> ls -al /usr/bin/pg_ctl
> lrwxrwxrwx 1 root root 32 Nov 15 14:16 /usr/bin/pg_ctl ->
> ../lib/postgresql/9.6/bin/pg_ctl*

To increase my understanding I want to resolve an apparent discrepancy in
versions.

After installing and initiating 9.6.1 that's reported as the current
running version, yet I've not yet migrated the cluster from 9.5.4 to 9.6.1.

Last week, after a kernel upgrade, I rebooted the system and re-started
postgres pointing to the 9.5/data/ directory. When I enter the command
'psql -l' I see all the databases and assumed they running on 9.5.4. But
that's not the case, is it?

If 9.6.1 is currently running after running initdb, and I can access my
databases, what does pg_upgrade do that's necessary?

A curious mind wants to learn,

Rich