Re: unexpected chunk number 2 (expected 0) for toast value ... inpg_toast_18536

On 3/15/20 12:20 PM, Karsten Hilbert wrote:
> On Sun, Mar 15, 2020 at 07:23:49PM +0100, Karsten Hilbert wrote:
> 
>> We then tried to DELETE the offending row
>>
>>     delete from blobs.doc_obj where pk = 82224;
>>
>> but that, again, shows the "unexpected chunk" problem.
> 
> According to
> 
>     http://www.databasesoup.com/2013/10/de-corrupting-toast-tables.html
> 
> an UPDATE of the row is recommended -- should that work
> better than a DELETE ?
> 
> I can't find documentation pointing to a fundamental
> implementation difference that suggests so.

https://www.postgresql.org/docs/12/storage-toast.html#STORAGE-TOAST-ONDISK

"During an UPDATE operation, values of unchanged fields are normally 
preserved as-is; so an UPDATE of a row with out-of-line values incurs no 
TOAST costs if none of the out-of-line values change."



> 
> Karsten
> --
> GPG  40BE 5B0E C98E 1713 AFA6  5BC0 3BEA AC80 7D4F C89B
> 
> 


-- 
Adrian Klaver
adrian.klaver@aklaver.com