Relationship Building: Defining and querying complex relationships between your content

The current story for relating content in Plone, via Archetypes reference fields, is limited and known to have poor performance in some cases. This talk will focus on the integration of Zope 3 tools for handling relationships (intids, zc.relationship) in Zope 2 via In particular I will be comparing the merits of these tools against existing methods (Archetypes references, using a separate RDBMS for content relationships), discussing particular applications for which they may be useful, and some areas in which they fall short. The comparison to existing relationship modeling tools will cover performance, flexibility, and convenience. To illustrate the relative convenience, I will give a brief overview of the API, from the lower level index and relationship container to the high level API for making queries and defining relationships. The discussion of applications will focus on a some real world uses. These include social networking, defining complex taxonomies, having content appear attached to multiple locations, and other things for which Plone typically would not be suitable (these tools are in use at In particular, I'll discuss how the default relationship attributes and query methods from the API can be used to model each of these applications. Finally, I'll discuss the areas in which these tools may fall short in terms of performance and flexibility, and where an RDBMS or specialized catalog may be necessary.