Well Knowns are NOT protected!

This morning began with a question: If a data set is deleted, what happens to the pages which are not also in another data set? Well first, these pages have an incomplete context. Second, they are accessible only via the directory structure. My conclusion is that they should be destroyed. (Which is consistent with previous implementations I've worked on.)

In looking back at the CompStrm home page, I see that there is an assumption that a well known is not subject to automatic destruction. It needs revising.

Now, does that mean that a well known is structurally part of the data sets that it is in? My answer here is no--a well known can be freely moved between data sets and may reside "in" more than one.

The Data data set should now be the only persistent well known, as it is the root in the (non-cyclic) data set bush structure. Further, the destruction of a strong property reference to a file not in the same structure should now be treated the same as if the property reference were to a member in the same structure--the referenced file, if not tagged as persistent, needs to be checked to see if it should be garbage collected.

This is an interesting refinement. A data sets is itself a well known and can be the root of a tree structure, that kind of structure being distinct from the structure of well knowns created from data sets and other well knowns.

(At this point I am very glad CompStrm is not in beta.)