Home > Archive > PostgreSQL Documentation > December 2005 > Re: [HACKERS] Online backup vs Continuous backup









You are viewing an archived Text-only version of the thread. To view this thread in it's original format and/or if you want to reply to this thread please [click here]

 

Author Re: [HACKERS] Online backup vs Continuous backup
Simon Riggs

2005-12-30, 9:23 am

On Mon, 2005-12-26 at 13:46 -0500, Bruce Momjian wrote:
> Tom Lane wrote:
>
> But why is it the standard terminology? It doesn't seem logical.


Well, as Greg says its a physical backup that can be done on-line, so
online backup makes perfect sense to me. I've never had somebody say
"that makes no sense" before. Nomenclature is different everywhere, I
accept.

I generally describe it like this:

Logical Backup
- use pg_dump - must be done on-line
Physical Backup
All file copy only
- must be Cold/Off-line backup
All file copy + WAL archiving
- allows Hot/Online or Cold/Offline backup

People understand those terms...

When do I mention PITR? Well, I describe this as Archive Recovery, with
an option to go to end-of-logs, or to a point-in-time.
[In the code, the mode variable is InArchiveRecovery.]

I do think that saying "do you use PITR?" makes little sense. We should
be talking about the backup mode, not the potential future recovery
mode.

I think it would all make more sense if we described the use of
archive_command = something as being in "WAL Archive Mode". That would
then allow us to say:
"You can only take Online Backups while in WAL Archive Mode".
"If you ever wish to perform PITR, you must use WAL Archive Mode".
"If you backed-up in WAL Archive Mode, you can perform an Archive
Recovery".

Best Regards, Simon Riggs



---------------------------(end of broadcast)---------------------------
TIP 3: Have you checked our extensive FAQ?

http://www.postgresql.org/docs/faq

Sponsored Links





Also available: Server administration forum archive | Web Design forum archive | Software forum archive | Hardware reviews archive | Programming forum archive

Copyright 2008 droptable.com