Deleting Objects from the 5800 System

The 5800 system client API exports an operation to delete a specific object as specified by its OID. Once a delete operation completes normally, subsequent attempts to retrieve that object will fail with an exception. In addition, the object will stop showing up in query result sets that match the original object metadata. There are no transactional guarantees regarding ordering of queries and delete operations that are occurring at the same time. If an object is being deleted at the same time that a query that matches that object is being performed, then that object may or may not show up in the query result set, with no guarantee either way.

When all objects that share an underlying block of data storage been deleted, the underlying block of data storage will itself be scavenged and returned to the supply of free disk space. But all details of how objects are stored, and how and whether they ever share data — or ever are scavenged — are outside of the scope of this API.

Delete operations are all-or-nothing,with some caveats. Specifically, if a delete operation fails with an error, it is possible that the object is not fully deleted but is temporarily not queryable. Such an object is in an analogous state to a store index exception (see The 5800 System Query Integrity Model). The queryability of such an object will eventually be resolved by automatic system healing. In addition, the queryability of such an object can be resolved under program control by using the checkIndexed method. Alternatively, the customer application may choose to re-execute the delete operation until it succeeds, or until it fails with an error that indicates the object is already deleted.