Re: Simple Upgrade from PostgreSQL version 8.1.11 (With schemas)

On 07/10/2012 11:28 PM, Chris Preston wrote:
> Hello all,
> How far can I get to a higher version of PostgreSQL by just entering a
> command line instruction to upgrade without any major effort?

Not very, unless your database and queries are very simple.

At minimum you'll have to deal with the removal of implicit casts to
text (
http://www.postgresql.org/docs/current/static/release-8-3.html#AEN116407) and,
if you use bytea, the change of default bytea format (
<http://www.postgresql.org/docs/9.0/static/runtime-config-client.html#GUC-BYTEA-OUTPUT>
http://www.postgresql.org/docs/current/static/release-9-0.html#AEN109764).

In general, you will want to read the "Migration to" notes for each version:

http://www.postgresql.org/docs/current/static/release-8-2.html
<http://www.postgresql.org/docs/current/static/release-9-0.html>
http://www.postgresql.org/docs/current/static/release-8-3.html
<http://www.postgresql.org/docs/current/static/release-9-0.html>
http://www.postgresql.org/docs/current/static/release-8-4.html
<http://www.postgresql.org/docs/current/static/release-9-0.html>
http://www.postgresql.org/docs/current/static/release-9-0.html
http://www.postgresql.org/docs/current/static/release-9-1.html
<http://www.postgresql.org/docs/current/static/release-9-0.html>

Alternately, you could try using PostgreSQL 9.1's pg_dump on your 8.1
database, load the dump into a 9.1 instance, run your client against it
and see what breaks. For simpler apps that can be a reasonable choice.

--
Craig Ringer