Re: roll back to 8.1 for PyQt driver work-around

Scott Frankel <frankel(at)circlesfx(dot)com> writes:
> Any suggestions for how best to launch one of two different versions
> of pg installed on the same machine?

> I have both 8.3 and 8.1 installed on a MacBookPro (OS X 10.5.2). I
> stopped the 8.3 postmaster using pg_ctl in order to roll back to 8.1.
> Problem is, now I can't seem to start the server using either version.

It looks like you're trying to use the same data directory for both
versions, which won't work. They're not compatible on-disk.

> When I launch 8.1 with pg_ctl, it yields a "postmaster starting"
> message; but then a status check shows that the server is not
> running. Issuing the same commands for 8.3, I get similar results.

Looking into the postmaster log file (your -l specification) might
yield some insight. pg_ctl itself doesn't really know why the
postmaster failed to start.

regards, tom lane