Re: Getting the first row from a select
Date: 1998/10/03
Message-ID: <Pine.OSF.3.95.981003013831.31806C-100000_at_gonzo.wolfenet.com>#1/1
On 3 Oct 1998, Christopher Browne wrote:
> ROWNUM is, in Oracle, effectively the physical location of the entry.
> Kind of like your telephone number; just because we just asked for the
> "B's" doesn't mean that the phone number gets reset to 1...
I think you are referring to ROWID, which in Oracle7 was of the form
"block.slot.file," and in Oracle8 is an opaque identifier that can be
decoded to provide the block, slot, and file of a row.
ROWID isn't really "assigned" at any time, but is rather more like an
address than the phone number in your analogy. It just means "this is
where the row is actually stored in the database." Indexes do physically
ROWNUM, on the other hand is just the counter of rows returned by a query.
-- Jeremiah Wilton http://www.wolfenet.com/~jeremiahReceived on Sat Oct 03 1998 - 00:00:00 CEST