[ZODB-Dev] BTrees questions

[Toby Dickenson]

On Wednesday 19 December 2001 2:59 pm, Jim Fulton wrote:

>BTree data structures certainly rely on sorting, which implies that
>keys must be orderable in a consistent fashion.  This is inherent
>in the underlying algorithm.  Given that the algorithm is based on
>ordering, using unordered keys is certainly something to worry about.
>Using integer and string keys is certainly worth worrying about.
>The problem here, however, is in the use of BTrees, not in BTrees
>themselves.

Agreed.

The potential real-world problem here relates to Zope's Catalog, which 
happily indexes whatever values it finds in an object's attributes without 
constraining type. My member account on zope.org lets me change my object's 
'Title' attribute to an integer today, which will break the whole index after 
upgrading to 2.2 (whenever that happens)


>Perhaps Python should not be so ready to order things in meaningless
>ways.

Indeed.

This is one area that C++ got right.