Re: Definition of Navigational (was: The wisdom of the object mentors)

> > Dbd can represent a thing in any number of "lists", "tables", "trees", "graphs", "networks", etc simultaneously without redundancy.
>
> That would imply that it uses pointers.

Consider that the same can be implemented with RMDBs.

> I am curious, how do you avoid orphan references when something is deleted?

By first deleting all reference to the thing being deleted :)

> Do you traverse the entire graph to delete any references to the just-removed item?

A combination of methods and traversing the entire network would be the last option.

> Do you "lock" the thing while this is happening? Or, is it single-threaded?

Currently it is single-threaded :(

> I suppose for this kind of app that a few orphans won't matter much.

In general, barring a hardware failure or a coding bug, there are no orphans. And user can't do anything to create orphans (ie disable or not specify referential integrity).

> A nightly batch job could clean them out.

The references are deleted immediately prior to actualy deleting selected thing.

> Human dreaming may be just such a purge stage, according to some researchers.

I am sure they are partially right. Received on Mon Jun 26 2006 - 17:03:58 CDT