Re: Retrieving records in order they were placed.

The sequence numbers would only wrap if the counter is too small. Oracle is capable of some pretty large numbers. If you define the sequence number as a column defined simply as NUMBER I bet it would take you a couple of lifetimes before it will wrap.

Ken

b_rich2_at_my-deja.com wrote:

> I have to put records into a table, and later retrieve them in the order
> in which they were placed. I have a very very large number of entries to
> be placed in a live system. The records are logs of important events in
> the system.
>
> My first thought was to use the unix time stamp to place as the field to
> order on, but there will probably be many entries entered in rapid
> succession. Thus many entries could be entered at the same time stamp
> interval.
>
> I then though of having a sequence number associated with each record,
> increasing one by one with each record stored. This will work well until
> the sequence numbers begin to wrap. If they are retrieved in order of
> sequence number, and then they wrap, the records entered after the wrap
> (sequences 1,2,3,4 etc) will all of a sudden be pulled out before the
> earlier records with high sequence numbers.
>
> Another idea is to just use the sequence numbers, and re-boot the box
> every few weeks when the sequence numbers get high, but this is really
> unacceptable in the environment where this will be run.
>
> Does anyone know how to get around this problem? Any help would be
> GREATLY appreciated.
>
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Received on Fri Jul 09 1999 - 08:17:14 CDT