Re: Allow WAL information to recover corrupted pg_controldata

-----Original Message-----
From: Robert Haas [mailto:robertmhaas@gmail.com]
Sent: Friday, June 22, 2012 8:59 PM
To: Amit Kapila
Cc: Tom Lane; Alvaro Herrera; Cédric Villemain; Pg Hackers
Subject: Re: [HACKERS] Allow WAL information to recover corrupted
pg_controldata

On Fri, Jun 22, 2012 at 5:25 AM, Amit Kapila <amit.kapila@huawei.com> wrote:
>> Based on the discussion and suggestions in this mail chain, following
features can be implemented:
>>
>> 1. To compute the value of max LSN in data pages based on user input
whether he wants it for an individual file,
>>   a particular directory or whole database.
>>
>> 2a. To search the available WAL files for the latest checkpoint record
and prints the value.
>> 2b. To search the available WAL files for the latest checkpoint record
and recreates a pg_control file pointing at that checkpoint.
>>
>> I have kept both options to address different kind of corruption
scenarios.

> I think I can see all of those things being potentially useful.

I shall start working on design and usage(how to provide these options to
users) of the features and present it once I am done.

> There are a couple of pending patches that will revise the WAL format
> slightly; not sure how much those are likely to interfere with any
> development you might do on (2) in the meantime.
Thanks.
I shall look into the patches (WAL Format change by Heikki and any other for
Logical Replication) to see which changes can effect the
implementation/design.


With Regards,
Amit Kapila.