> >Details:
> > Solaris 9 sparc, 7.3.13, compiled with --thread-safety
>
> Upgrade this version ASAP.  The following bug, fixed in 7.4.8, reared
> it's ugly head around here corrupting replica's with a duplicate key
> violation errors and making several DBA's very cranky...
>
> http://www.postgresql.org/docs/7.4/static/release-7-4-8.html

I believe that this issue was fixed in 7.3 around 7.3.10.  7.3.13 is the 
latest in the 7.3 series.  Unless I'm looking at the wrong bug/fix?

> >I was able to manually remove the offending rows and get the slon's
> > processing events again, but I'm worried about a few things:
> >
> >1. How is my data?  Do I need to re-sync?
>
> Where did you remove the offending rows from?  If you manually removed
> the row from sl_log_1, leaving the data on the master, but not the
> subscriber, then your replica is shot.

I removed the offending row in the slave table:
 begin;
     update pg_class set reltriggers=0 where relname = 'the_table';
     delete from the_table where primary_key = 'the_rows_pk_val';
     update pg_class set reltriggers=1 where relname = 'the_table';
 commit;

After this, slon successfully processing the event group.

> Since moving to 7.4.8, we haven't had the replica corrupting scenario.
> We have seen the duplicate key violation error on occasion, but the
> problem was with a bad index on the table being replicated to.
> Reindexing that table on table on the subscriber fixed the problem.

I don't think that this is my issue, as I could see that the row was actually 
present.  Additionally, it appears the other changes from the same event 
group had also been previously processed, but I can't be positively sure.

Thanks,

  Michael