Carolyn Lu Wong <carolyn@greatpacific.com.au> writes:
> anyone knows if duplicated oid is possible??
Yes, if you don't have a unique index on it and you've generated more
than four billion rows in the database.
> is there a possible way to remove the duplicate row, now that i don't
> know which ID to use? any suggestions?
Use ctid to distinguish the rows. Note ctid will change if you update
a row, so it's not a permanent identifier either, but it will serve for
deleting a row.
regards, tom lane
