A day late and a dollar short but here's my $.02
Order will give you the temporal sequencing. Nocache should but it's not
certain.
Cached numbers are stored in the SYSTEM tablespace and can be retrieved in
an atemporal order. I can't give you any specifics, but that's what Oracle
says. Nocached numbers are generated at call time but that doesn't mean
that they'll be stored in the database in temporal order. Order means that
the number will be generated and stored in temporal order. As you can
guess, this slows things up a bit. You will almost certainly see an
increase in locking with ordered sequences. It can also happen with
nocache.
We recently went through an exercise of looking at every sequence in our
database, about 400 altogether, to see if they needed to be ordered and
cached. None of them needed to be ordered. Your requirement is unusual.
If the sequence was being hit once an hour or so we decided to nocache it
(save churning the SYSTEM tablespace). But our defaults are cache and
noorder.
HTH
"Gogala,
Mladen" To: Multiple recipients of list ORACLE-L
<[EMAIL PROTECTED]>
<MGogala cc:
@oxhp.com> Subject: OPS Sequences: nocache == order
??
Sent by: root
09/03/2002
06:00 PM
Please
respond to
ORACLE-L
I'm managing an OPS configuration (4x HP 9000/N, HP-UX 11/64 , RDBMS
8.1.7.1)
and I'm having an application dependency on a temporal order of sequence
numbers.
With OPS that becomes a problem because each node caches a set of sequence
numbers
(20 by default). Oracle has an option, specifically for that situation,
namely "ORDER".
My question is whether ORDER is the same thing as NOCACHE and whether it
is possible
to have a NOCACHE sequence which will return numbers in an incorrect order
(larger number
before the smaller one).
Please, o OPS gods and godesses, help me out and I'll sacrifice you a beer
when I see you.
Mladen Gogala
--
Please see the official ORACLE-L FAQ: http://www.orafaq.com
--
Author: Thomas Day
INET: [EMAIL PROTECTED]
Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051
San Diego, California -- Public Internet access / Mailing Lists
--------------------------------------------------------------------
To REMOVE yourself from this mailing list, send an E-Mail message
to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in
the message BODY, include a line containing: UNSUB ORACLE-L
(or the name of mailing list you want to be removed from). You may
also send the HELP command for other information (like subscribing).
