Re: pg_upgrade and rsync

On 1/29/15 6:25 PM, David Steele wrote:
> Safe backups can be done without LSNs provided you are willing to trust
> your timestamps.

Which AFAICT simply isn't safe to do at all... except maybe with the manifest stuff you've talked about?

>> >FWIW, I personally am very leery of relying on pg_upgrade. It's too
>> >easy to introduce bugs, doesn't handle all cases, and provides no
>> >option for going back to your previous version without losing data. I
>> >much prefer old_version -- londiste --> new_version, and then doing
>> >the upgrade by reversing the direction of replication.
> I think the official docs need to stick with options that are core?

I don't think we have any such requirement. IIRC the docs used to talk about using logical replication before we had pg_upgrade (and may have actually called out Slony).

> I avoid pg_upgrade wherever it is practical. However, sometimes it
> really is the best option.

Certainly. I think what we should be doing is spelling out the available options (with pros/cons) so that users can decide what's best.

>> >I also don't entirely trust PITR backups. It's too easy to
>> >accidentally break them in subtle ways.
> Agreed in general, but I've been doing a lot of work to make this not be
> true anymore.

:)

I'd love to see all this stuff Just Work (tm), but I don't think we're there yet, and I'm not really sure how we can get there.
--
Jim Nasby, Data Architect, Blue Treble Consulting
Data in Trouble? Get it in Treble! http://BlueTreble.com