Re: Symmetric Replication : Dynamic Ownership

Andre Vergison <avergison_at_infosoft.be> wrote:

>Talking about symmetrically replicated sites, where each site owns a
>given range of rows of the same (replicated) table, and the ownership
>of a row is determined by values within it.
 

>How is ownership of a range of rows actually defined ?
>Can I inhibit inserts into such a range on a given site that does not own
>rows in this range ? I understand that updates and deletes wouldn't be
>permitted, but does this also hold true for inserts (kind of 'range
>lock') ?
 

>Thanks

Andre, remember that dynamic ownership basically relies on 'well behaved applications' i.e. the application checks that the data conforms to whatever ownership rules you want to apply before making any change to the data.

Simple example: have an OWNERSHIP column in the replicated tables and only allow updates to rows where the value of this column is your site.

More complex: derive the ownership from the information already in the table - in an order processing system you only let the Billing department alter data where SHIP_DATE != NULL (ie the product has been shipped).

So, you could prevent inserts by performing a PRE-INSERT check on the data about to be inserted in your application.

Hope that helps.

Dave Received on Fri Dec 08 1995 - 00:00:00 CET