Re: unable to repair table: missing chunk number

When faced with a similiar sounding problem I tried the following with 
some success.  It is an extreme alternative and not suited to all 
situations...that having been said, here goes.

pg_dump mytable >> mytable.txt

You said
 > When I dump the table to disk I get records in sequence by primary key
 > from 1 to 115847 before it crashes.

I looked at the mytable.txt file and found the last entry that pg_dump 
was able to copy and noted the primary key number (115847).

I then executed a quiery that deleted the very next primary key number 
(115848) record.  (*BAD!  Lost that data record.  BAD!*)

I was then able to do a pg_dump of the entire table followed by a 
vacuum/analyze.  (*Good.  PG is running correctly. Good*)

In my singular case the loss of one data record is acceptable.  It may 
not be for you.  Try this resolve only at your own risk and peril.

Peace

- Bill