Oracle-L: RE: sequence question

From: Reardon, Bruce (CALBBAY) <Bruce.Reardon_at_comalco.riotinto.com.au>
Date: Thu, 13 Jun 2002 18:43:22 -0800
Message-ID: <F001.0047DB5C.20020613184322@fatcity.com>

Short answer - yes you could loose some numbers.

Have a look at http://www.ixora.com.au/scripts/library.htm and the unload_sequences.sql and keep_sequences.sql which mention that you can lose when:

	Shutdown abort is done
	the sequence gets aged out of the library cache

The scripts suggest 2 ways to help avoid this.

If its really critical to never skip a number then maybe you shouldn't cache the sequence. But then again, if its that critical maybe you shouldn't use a sequence - eg what if someone gets the sequence number and then does a rollback.

It is my understanding from a simple test that you will now have a "hole / gap" in the sequence numbers.

So, does a gap REALLY matter (ie can you never have a gap) or is it just that you need to avoid gaps where possible.

HTH,
Bruce Reardon

-----Original Message-----

Sent: Friday, 14 June 2002 11:23

Hi List ,
I want to create a sequence which will be used by some external process to generate some unique number . since this sequence will be used very frequently I would prefer to cache around 10000 numbers . Am I going to loose some numbers ? what is SEQUENCE_CACHE_ENTRIES and how does it affect number or sequence cached ?

Thanks ,
-Bp
--

Please see the official ORACLE-L FAQ: http://www.orafaq.com
--

Author: Reardon, Bruce (CALBBAY)
INET: Bruce.Reardon_at_comalco.riotinto.com.au

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: 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 Thu Jun 13 2002 - 21:43:22 CDT