Re: Sequence missing values

From: Dave Wotton <Dave.Wotton_at_no-spam.it.camcnty.gov.uk>
Date: 12 Oct 1998 12:24:32 GMT
Message-ID: <6vsse0$fdd$1@dns.camcnty.gov.uk>

> ...
>After the procedures have been run it appears that the sequence has
>been missing certain values. e.g a value that we had expected to be
>1001 is actually 1009. The jump seems to be random. Does anyone have
>*any* idea what could be causing this. Apart from the obvious ones
>like somebody else getting the nextval, which is not happening.

Hi,

this problem has been described and solved several times before in this newsgroup. It is described on Page 2-18 of the "Oracle 7 Server Application Developers Guide." As someone else said, it's to do with the way Oracle caches sequences ( and the effect of the sequence_cache_entries init.ora parameter ). To guarantee no skipping, alter your sequences to be NOCACHEd. It has nothing to do with how many processors your machine has or how many instances you're running in parallel. A single instance on a single processor will also exhibit the problem.

If you haven't got access to the manuals, try searching Dejanews for references to sequences. ( I've answered the question in more detail at least once before :-) ).

HTH, Dave.
--
Remove the no-spam bit from my email address to reply. Received on Mon Oct 12 1998 - 07:24:32 CDT