Re: Hot standby, recovery infrastructure - Mailing list pgsql-hackers

From Heikki Linnakangas
Subject Re: Hot standby, recovery infrastructure
Date
Msg-id 497F4E68.5070308@enterprisedb.com
Whole thread Raw
In response to Re: Hot standby, recovery infrastructure  (Simon Riggs <simon@2ndQuadrant.com>)
Responses Re: Hot standby, recovery infrastructure  (Simon Riggs <simon@2ndQuadrant.com>)
List pgsql-hackers
Simon Riggs wrote:
> On Tue, 2009-01-27 at 17:50 +0200, Heikki Linnakangas wrote:
> 
>> Hmm, I think we have small issue if the last WAL segment restored from
>> the archive is an incomplete one:
> 
> All normal archive recoveries have "complete" WAL files, since an xlog
> switch record jumps past missing entries at the end of the file. So I
> was just about to say "how can it be an incomplete one?", to which the
> answer is file damage of some kind causing a failed CRC check.
> 
> So yes, it is possible and no, the patch doesn't work that way yet.

Actually, the code already deals with that possibility. That's the 
motivation for the timelines: the new WAL record will be generated with 
a new timelineid. We never append to an existing WAL file after archive 
recovery.

--   Heikki Linnakangas  EnterpriseDB   http://www.enterprisedb.com


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