Re: Review: Patch to compute Max LSN of Data Pages

On 2013-07-08 17:10:43 +0530, Amit Kapila wrote:
> On Monday, July 08, 2013 4:26 PM Andres Freund wrote:
> > On 2013-07-08 16:17:54 +0530, Hari Babu wrote:
> > > +    This utility can also be used to decide whether backup is
> > required or not when the data page
> > > +    in old-master precedes the last applied LSN in old-standby
> > (i.e., new-master) at the
> > > +    moment of the failover.
> > > +   </para>
> > > +  </refsect1>
> > 
> > I don't think this is safe in any interesting set of cases. Am I
> > missing
> > something?
> 
> No, you are not missing anything. It can be only used to find max LSN in
> database which can avoid further corruption 

Why is the patch submitted documenting it as a use-case then? I find it
rather scary if the *patch authors* document a known unsafe use case as
one of the known use-cases.

Greetings,

Andres Freund

-- Andres Freund                       http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training &
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