Base Classes for Trees

[wiz]

Base classes, what could efficiently handle large tree-like structures.

• Recursive handling (delete, move, rebuild, and so)
• Querying for children in some ways, with filters
  • Nearest
  • By path
  • Level[s] slice
  • Parents
• Node data types handling. Mapping to other classes.

I think it would be 2 classes: one for handling tree structure and one base class for node items.

[rjwittams]

The best discussion of the issues of hierarchical data in SQL I've seen is Chapter 7 of Practical Issues in Database Management by Fabian Pascal. In short, its not pretty.

[imbaczek]

php has this thing called Nested Set in PEAR. It adds a _lot_ of information to the table, but allows for very efficient subtree selections.

[Jacob]

I'm pretty sure this is complex enough (and has enough different possible implamentations) that it really shouldn't be part of Django proper.