Re: sequences with cache option

Your problem definately has to do with the cache option.

What is happening is that when you startup the Oracle instance, the sequence takes the next 20 values from the sequence and stores it in a buffer ( or cache memory), and the sequence is incremented likewise.

If you shut down the instance, these sequence numbers are lost because they are in RAM, but the sequence stays the same.

This is why you have these funny jumps in your sequence numbers.

Roy Klassen rklassen_at_pei.sympatico.ca

Ron Chapman <ronc_at_jagman.com> wrote in article <33FA1164.9BDA8F63_at_jagman.com>...
> We are noticing some erratic sequence jumps with our Orcacle 7.3.2
> server. The sequence was created with the following statement:
>
> CREATE SEQUENCE customer_id
> INCREMENT BY 1
> START WITH 50
> MAXVALUE 99999999
> ORDER NOCYCLE;
>
> We left out the cache option because Oracle will use a default of 20.
> We are noticing that the sequence will jump by a maximum increment of 20
> sometimes, but definitely not every time. The amount of the increment
> does not seem to be constant. We've checked our code, GUI, and create
> scripts and have been able to rule them out as the possible culprit. We
> are starting to believe that this may have something to do with the
> cache option, but have been unable to find any documentation that might
> explain this.
>
> Any help would be appreciated.
>
>
> Ron Chapman
> ronc_at_jagman.com
>
>
  Received on Wed Aug 20 1997 - 00:00:00 CDT