Re: Warm Standby and resetting the primary as a standby

Derrick Rice wrote:
> I've been reading up on the documentation for WAL shipping and warm standby
> configuration. One concern that I have (a common one, I'm sure) is that it
> seems that after bringing a standby server up as primary, other standby
> servers (including the original primary) need to be rebased before they can
> read the new primary's WALs in continuous recovery mode.
>
> It seems that the cause of this is a change to the leading digit of the WAL
> files:
>
> http://archives.postgresql.org/pgsql-general/2010-03/msg00985.php
> http://archives.postgresql.org/pgsql-admin/2009-08/msg00179.php
>
> I was hoping that someone would shed some light on this situation with a
> technical explanation.  It's not clear to me why the WAL files are
> incompatible or why the digit increases. What does that first digit mean to
> postgresql?  Is it possible to have the restore_command ignore the leading
> digit?

The first digit in the WAL filename is the timeline.

I think we need to figure out a better way to promote slaves when there
is a new master, but no one has done the research yet.

--
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  + It's impossible for everything to be true. +