| Oracle FAQ | Your Portal to the Oracle Knowledge Grid | |
 |
 | |||
| Oracle FAQ | Your Portal to the Oracle Knowledge Grid | |
|
| |||
Home -> Community -> Mailing Lists -> Oracle-L -> RE: Sequences in OPS/RAC
Hemant,
I would guess that this is true if you are caching values for the sequence. Each database instance might cache the same set of values.
Turn sequence caching off, and I would think that the problem goes away.
Havn't tried this in awhile, but it makes sense.
Tom Mercadante
Oracle Certified Professional
-----Original Message-----
Sent: Monday, November 03, 2003 10:39 AM
To: Multiple recipients of list ORACLE-L
I have always been comfortable with the idea that Sequences continue to
guarantee
uniqueness even in OPS / RAC environments.
However, a recent Builder.Com article by Scott Stephens on the SYS_GUID
function has these lines :
"Sequence generator numbers are guaranteed to be unique only for a single
instance, which is unsuitable for use as a primary key in parallel or
remote environments, where a sequence in each environment might generate
the same number and result in conflicts. An identifier created by SYS_GUID
is guaranteed to be unique for each database."
Huh ?! Do the lines mean that a single sequence can have duplicate values in the two instances of an RAC cluster ?
Hemant K Chitale
Oracle 9i Database Administrator Certified Professional
My personal web site is : http://hkchital.tripod.com
--
Please see the official ORACLE-L FAQ: http://www.orafaq.net
--
Author: Hemant K Chitale
INET: hkchital_at_singnet.com.sg
Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services ---------------------------------------------------------------------To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (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).
Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services ---------------------------------------------------------------------To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (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). Received on Mon Nov 03 2003 - 09:49:26 CST
 |
 |