Re: Allow WAL information to recover corrupted pg_controldata

Fujii Masao <masao.fujii@gmail.com>

From: Fujii Masao <masao.fujii@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>, Robert Haas <robertmhaas@gmail.com>

Date: 2012-06-19T14:14:13Z

Lists: pgsql-hackers

On Tue, Jun 19, 2012 at 2:44 AM, Amit Kapila <amit.kapila@huawei.com> wrote:
>> AFAIR you can create pg_control from scratch already with pg_resetxlog.
>> The hard part is coming up with values for the counters, such as the
>> next WAL location.  Some of them such as next OID are pretty harmless
>> if you don't guess right, but I'm worried that wrong next WAL could
>> make things worse not better.
>
> I believe if WAL files are proper as mentioned in Alvaro's mail, the purposed logic should generate
> correct values.
> Do you see any problem in logic purposed in my original mail.
> Can I resume my work on this feature?

Maybe I'm missing your point, but... why don't you just use PITR to
recover from the corruption of pg_control?

Regards,

-- 
Fujii Masao