[Zope-dev] difference between OOSet and OOTreeSet?

[Tim Peters]

[Chris Withers]
> Wondering if someone could tell me the difference between an OOSet and
> an OOTreeSet?

OOSet is to OOTreeSet as OOBucket is to OOBTree.  An OOTreeSet is
built out of leaf-level OOSets in exactly the same way an OOBTree is
built out of leaf-level OOBuckets.  More at:

http://wiki.zope.org/ZODB/guide/node6.html#SECTION000630000000000000000

> They seem to have different interfaces

?

> and yet seem to be used in
> similar circumstances in PluginIndexes/common/UnIndex.py...
>
> I'm looking for a set-like data structure which will likely get pretty
> large over time and so I don't want the whole data structure written to
> disk each time I add a new item to the set.
>
> What should I be using?

OOTreeSet.