Re: how to implement a circular buffer in a table

On Wed, 15 Aug 2001 22:44:33 -0400, "Stephen T. Parfitt" <steve.parfitt_at_sympatico.ca> wrote:

>Create a SEQUENCE with a MAXVALUE and the CYCLE option ... then use this
>sequence as the primary key. Presumably, you will need a bit of logic
>to do INSERTs on the first cycle and UPDATEs thereafter when the
>circular buffer is overwriting itself - or else initialize the buffer
>with dummy values beforehand.
>

Good idea, the sequence.
And write the logic in a PL/SQL package exposing only an INSERT and a SELECT methods. Rollback to the begin of buffer can be achieved by a package global boolean that gets reset once EOF is reached. Works for me...
Cheers
Nuno Souto
nsouto_at_optushome.com.au.nospam Received on Thu Aug 16 2001 - 07:51:17 CDT