Re: Sequence Number Re-use is it possible, what is the standard

If you have 200 concurrent users of this sequence, you want to consider not using no cache. Else you will see wait events on enqueue for trying to allocate a new sequence number (SQ enqueue).

Anjo.

Michel Cadot wrote:

> "Sybrand Bakker" <postbus_at_sybrandb.demon.nl> a écrit dans le message news:
> 57fq9tkfvmsqnsja55sd70o6blbq2dt33d_at_4ax.com...
> > On Wed, 28 Feb 2001 16:59:37 GMT,
> > u28656005_at_spawnkill.ip-mobilphone.net wrote:
> >
> > >We have a system that uses a Sequence table to get id's for our bids.
> > >
> > >In our application the user might click new, which gets the nextval.
> > >
> > >But if they click new again, or they close the program, we obviously
> > >
> > >lose that number from the sequence table. What do most people do about
> > >
> > >this. We really don't want to lose this number, and there will
> > >
> > >eventually be over 200 users getting unique id's from our sequence. So
> > >
> > >unused numbers can go pretty rapidly.
> > >
> > >Has anyone done something like, put the unused numbers into a table,
> > >
> > >have the program first look to see if there are any record in this
> > >
> > >table, and grab one of these numbers and uses it, and if they find no
> > >
> > >records it goes to the sequence table. Is this a stupid idea?
> > >
> > >
> > >
> > >Inquiring minds want to know
> > >
> > >Thank you very much for your help.
> > >
> > >
> > >
> > >Mark
> > >
> > Use the nocache option of the create sequence command, which will at
> > least take away the buffer of pre-created sequence numbers, and for
> > the rest : don't bother. The maximum sequence number is 2^32 -1, which
> > you probably won't even reach before you retire.
> >
> > Hth,
> >
> >
> > Sybrand Bakker, Oracle DBA
>
> I agree with Sybrand except for the maximum sequence number which
> is 999999999999999999999999999 in Oracle7 and 10**27 with Oracle8i.
>
> --
> Cheers
> Michel
Received on Thu Mar 01 2001 - 05:56:33 CST