...
> The oid correctly reflects the order of the insertion of the rows...
> but look at the timestamp - the last row has a timestamp _2 minutes
> before_ the previous row. How could this be happening? We know row
> 69719 was inserted _after_ 69718, by probably about 30 seconds.
The timestamp provided as a result of evaluating 'now' is the time of
the start of the transaction, not the instantaneous wall clock time (if
you want the latter there is a function to provide it).
So, the times will reflect the time the transaction was started, while
the OID will reflect the order in which the insert/update actually
happened within the transaction.
hth
- Thomas