Search Postgresql Archives

Re: unexpected chunk number 2 (expected 0) for toast value ... in pg_toast_18536

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Sun, Mar 15, 2020 at 12:58:53PM -0700, Adrian Klaver 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."

However, where is the fault in my thinking ?

-> An UPDATE actually *would* change the TOASTed BYTEA field (which is corrupt).

I had hoped that the DELETE would NOT have to touch the TOAST
table at all (and thereby not check the chunks) as "all it
needs to do" is mark the row in the *primary* table as
not-needed-anymore.

I must be misunderstanding something.

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






[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [Postgresql Jobs]     [Postgresql Admin]     [Postgresql Performance]     [Linux Clusters]     [PHP Home]     [PHP on Windows]     [Kernel Newbies]     [PHP Classes]     [PHP Books]     [PHP Databases]     [Postgresql & PHP]     [Yosemite]

  Powered by Linux