Re: WAL segment question

On Sat, 2007-08-04 at 00:00 +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 WAL file 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 master database site, at
> the point of failure, without starting the database up?

Currently there is no built-in means of finding out the time of the last
record transferred, if the primary stays down. You need to use xlogdump
to locate the time of the last commit/abort record.

--
  Simon Riggs
  EnterpriseDB  http://www.enterprisedb.com