Re: Fixing up a corrupted toast table

On Feb 17, 2006, at 8:27 AM, Steve Atkins wrote:

>
> On Feb 17, 2006, at 6:29 AM, Tom Lane wrote:
>
>> Steve Atkins <steve(at)blighty(dot)com> writes:
>>> pg_dump: ERROR: missing chunk number 0 for toast value 25923965
[snip]

>>
>> If that doesn't work, the standard technique for locating damaged
>> data
>> should help: find the bad row by identifying the largest N for which
>> "SELECT * FROM table LIMIT n" doesn't fail, then "SELECT ctid FROM
>> table
>> OFFSET n LIMIT 1". You may be able to delete the bad row with
>> "DELETE
>> FROM table WHERE ctid = 'value gotten above'", but I wouldn't be too
>> surprised if the DELETE gives the same error. If so, you can
>> probably
>> make it happy by inserting a dummy row into the toast table (chunk ID
>> as specified in the error, chunk sequence 0, any old data value).
>
> OK, that's what I was looking for. Thanks!

Unfortunately, postgresql is smarter than I am.

Any attempt to touch the toast table gives me:

ERROR: cannot change TOAST relation "pg_toast_17410"

If I set relkind to 'r' for the toast table, shove some fake data
in there and set it back to 't' that should do it, shouldn't it?

Cheers,
Steve