> I don't think it is actually random.  It just that the order is not defined
> and other events may change the order.  I believe that without an ORDER BY
> or other clauses that cause an index to be used that the database tends to
> return rows in the order stored on disk.  This order tends to be the order
> in which rows were added.  My observation is this ordering is faily stable
> and it seems to survive a database reload.  Just don't rely on it.  There is
> a CLUSTER command to change the physical ordering.

Yes, usually it is the heap order, but if you do "col > 12" you may get
it in index order by the column indexes, or you may not, depending on
the constant, the size of the table, vacuum, vacuum analyze, etc.

-- 
  Bruce Momjian                        |  http://candle.pha.pa.us
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