Re: [PATCH] Patch to compute Max LSN of Data Pages - Mailing list pgsql-hackers

From Amit kapila
Subject Re: [PATCH] Patch to compute Max LSN of Data Pages
Date
Msg-id 6C0B27F7206C9E4CA54AE035729E9C3828548CBA@szxeml509-mbx
Whole thread Raw
In response to Re: [PATCH] Patch to compute Max LSN of Data Pages  (Alvaro Herrera <alvherre@2ndquadrant.com>)
Responses Re: [PATCH] Patch to compute Max LSN of Data Pages  (Fujii Masao <masao.fujii@gmail.com>)
List pgsql-hackers
On Monday, November 12, 2012 9:56 PM Alvaro Herrera wrote:
Robert Haas escribió:
> On Tue, Jul 31, 2012 at 8:09 AM, Amit kapila <amit.kapila@huawei.com> wrote:

>> >> 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.
> >
>> > Based on above conclusion, I have prepared a patch which implements Option-1
>
>> I wonder if we shouldn't make this a separate utility, rather than
>> something that is part of pg_resetxlog.  Anyone have a thought on that
>> topic?

> That thought did cross my mind too.

One of the reasons for keeping it with pg_resetxlog, is that this was proposed as a solution for scenario's where
user'sdb has become corrupt and now he 
want to start it. So to do it he can find the max LSN and set the same using pg_resetxlog, it will avoid the further
corruptionof database after it got started. 
If we keep it a separate utility then user needs to first run this utility to find max LSN and then use pg_resetxlog to
achievethe same. I don't see a big problem in that 
but may be it would have been better if there are other usecases for it.


However it might be used for other purpose also which I am not able to think.

Do you have any particular reasons for having it a separate utility?

With Regards,
Amit Kapila.







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