Question on Wal time lines

Started by dabichoalmost 15 years ago4 messagesgeneral
Jump to latest
#1dabicho
tsukebumi@gmail.com

For restoring a database from wal files, if I omit a target on the
recovery.conf file, can I make it so the database continues the time line
instead of starting one?
Or is there a tool to pick the most recent time line from a bunch of wal
files?

thankyou.

#2John R Pierce
pierce@hogranch.com
In reply to: dabicho (#1)
Re: Question on Wal time lines

On 05/03/11 3:07 PM, dabicho wrote:

For restoring a database from wal files, if I omit a target on the
recovery.conf file, can I make it so the database continues the time
line instead of starting one?
Or is there a tool to pick the most recent time line from a bunch of
wal files?

thankyou.

you need to playback all the wal files from when you started the base
backup. of course, you need that base backup, too.

#3dabicho
tsukebumi@gmail.com
In reply to: John R Pierce (#2)
Re: Question on Wal time lines

El may 3, 2011 5:59 p.m., "John R Pierce" <pierce@hogranch.com> escribió:

On 05/03/11 3:07 PM, dabicho wrote:

For restoring a database from wal files, if I omit a target on the

recovery.conf file, can I make it so the database continues the time line
instead of starting one?

Or is there a tool to pick the most recent time line from a bunch of wal

files?

thankyou.

you need to playback all the wal files from when you started the base

backup. of course, you need that base backup, too.

I did that.
I restored the database, put the recovery file in place along with previous
wal files and the last wall files, and after start up there was a new time
line.
Am I missing something?
This is postgres 9.0

Show quoted text

--
Sent via pgsql-general mailing list (pgsql-general@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-general

#4Greg Smith
gsmith@gregsmith.com
In reply to: dabicho (#1)
Re: Question on Wal time lines

dabicho wrote:

For restoring a database from wal files, if I omit a target on the
recovery.conf file, can I make it so the database continues the time
line instead of starting one?
Or is there a tool to pick the most recent time line from a bunch of
wal files?

When recovery finishes, you get a new timeline. That way it's always
possible to distinguish between a server that's exited recovery, and
started generating new WAL data, from one that is still sync'd to the
master and running recovery of the original timeline. If you don't want
a new timeline, don't let recovery finish.

As for the options you can tweak, see
http://www.postgresql.org/docs/9.0/static/continuous-archiving.html#BACKUP-TIMELINES
and the recovery target parameters at
http://www.postgresql.org/docs/9.0/static/recovery-target-settings.html
You can navigate among multiple timelines in a set of WAL files using
recovery_target_timeline and the other target settings. It really is
worth the trouble to run some experiments with these ideas to see what
you can do, before you're forced to do so by an emergency.

--
Greg Smith 2ndQuadrant US greg@2ndQuadrant.com Baltimore, MD
PostgreSQL Training, Services, and 24x7 Support www.2ndQuadrant.us
"PostgreSQL 9.0 High Performance": http://www.2ndQuadrant.com/books