Re: unable to repair table: missing chunk number

Hi Tom,

> A brute-force way to narrow things down would be to write a little
> program that tries to retrieve each row individually by primary key,
> starting at 115848 since you know the rows before that are okay.

Thanks, this worked. I ran a perl script that went from 1 to
max(primary_id), and selected a record and then inserted it into a new
table. 

There were a total of two bad records, so not too bad. =)

> That's disturbing; short of a serious failure (disk crash, for instance)
> I don't know of anything that would cause this.
> 
> One thing that would be interesting to try is to investigate the TOAST
> table directly.  

# select oid from pg_class where relname = 'users';
   oid   
---------
 9361620
(1 row)

# select chunk_seq, length(chunk_data) from pg_toast_9361620 where 
  chunk_id = 12851102 order by chunk_seq;

 chunk_seq | length 
-----------+--------
(0 rows)

Very strange. 

Now that we can backup the data, we've switched the database to a brand
new disk drive, and re-imported and vacuumed everything. The application
is running smoothly again.

I doubt this is relevant, but we were symlinking /usr/local/pgsql/data
-> /mnt/disk2/pgsql. Also, one column in the problem table was a text
field avg'ing 20k.

I still have the old database if it helps.

Thanks for all your help,

Alex