Re: WAL segment question

On Sat, Aug 04, 2007 at 12:00:52AM +0100, Donald Fraser wrote:
> Our company has two sites, a master and a disaster recovery site.
> I am trying to assess whether data has been lost during a fail-over, due to the asynchronous method of transporting
WALfile data between sites (we use DRBD). 
>
> Disaster recovery node start-up log:
> user= pid=9907 timestamp=[2007-08-01 17:09:51 BST] tid= LOG:  record with zero length at 0/7C62F52C
> user= pid=9907 timestamp=[2007-08-01 17:09:51 BST] tid= LOG:  redo done at 0/7C62F4E8
>
> My question is: given the above WAL segment information, can I use it to decide whether information was lost in the
masterdatabase site, at the point of failure, without starting the database up? 

I'm not sure, but you could try md5-ing the appropriate WAL file on the
master and slave; if the files are identical then you shouldn't have
lost any data... if they are then you probably have.
--
Decibel!, aka Jim Nasby                        decibel@decibel.org
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