Hi Adrian,

Thanks Adrian for you quick reply. I am looking in this that why db came into 
this stage.

--I have found overheating servers to be particularly prone to index corruption 
and if indexes can get corrupt one has to worry about data becoming ---corrupt 
too.

Is the above statement true?
What is the meaming of toasted values?
What is this pg_toast? Can you please share any link on this?

Note from the shared link
--------------------------------------

Given that what you did was a reindex, what probably happened was it used an 
index scan to try to locate the toasted values in the table and couldnt find 
one. This sounds like a corrupted index. Vacuum analyse does alter the table 
but reindex does not and the changes are very minor.

The way to think about this is that TOASTed attributes are actually broken into 
chunks of about 4k in size and these are stored in rows. They are looked up and 
sorted/reconnected with the main row at query time. It sounds like an index 
used here was corrupted and so the reindex solved the problem.

I have found corrupted indexes are usually a sign that something is not well 
with the server. It is good to check and make sure memory, CPU's and hard 
drives are all happy and not reporting problems. I have found overheating 
servers to be particularly prone to index corruption and if indexes can get 
corrupt one has to worry about data becoming corrupt too.


Regards
Tarkeshwar

-----Original Message-----
From: Adrian Klaver [mailto:adrian.kla...@aklaver.com] 
Sent: 03 December 2014 20:22
To: M Tarkeshwar Rao; pgsql-general@postgresql.org
Subject: Re: [GENERAL] FW: getting error while running sql on mm_activealrm 
table

On 12/03/2014 03:07 AM, M Tarkeshwar Rao wrote:
> Hi all,
>
> We are getting following error message on doing any action on the 
> table like(Select or open from pgadmin).
>
> Please suggest.
>

http://dba.stackexchange.com/questions/31008/pg-dump-and-error-missing-chunk-number-0-for-toast-value

Though the question still remains, what got it into that state?

Any recent hardware/software issues?

>
> Regards
>
> Tarkeshwar
>


--
Adrian Klaver
adrian.kla...@aklaver.com


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