Re: Review: Patch to compute Max LSN of Data Pages - Mailing list pgsql-hackers

From Amit Kapila
Subject Re: Review: Patch to compute Max LSN of Data Pages
Date
Msg-id CAA4eK1JBKNPFJ2=XLjtXbSYn3_S7wa9kfai0GKoPr--aNNCedQ@mail.gmail.com
Whole thread Raw
In response to Review: Patch to compute Max LSN of Data Pages  (Muhammad Usama <m.usama@gmail.com>)
Responses Re: Review: Patch to compute Max LSN of Data Pages
List pgsql-hackers
>On Monday, July 08, 2013 5:16 PM Andres Freund wrote:
>>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.

>I got the problem which can occur with the specified use case. Removed the
>wrong use case specified above.
>Thanks for the review, please find the updated patch attached in the mail.

Patch is not getting compiled on Windows, I had made following changes:
a. updated the patch for resolving Windows build
b. few documentation changes in (pg_resetxlog.sgml) for spelling
mistake and minor line change
c. corrected year for Copyright in file pg_computemaxlsn.c


With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com

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