Re: Allow WAL information to recover corrupted pg_controldata

Robert Haas <robertmhaas@gmail.com>

From: Robert Haas <robertmhaas@gmail.com>
To: Amit Kapila <amit.kapila@huawei.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Alvaro Herrera <alvherre@commandprompt.com>, Cédric Villemain <cedric@2ndquadrant.com>, Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2012-06-22T15:29:18Z
Lists: pgsql-hackers
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.  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.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company