This post is a recent, non-confidential internal memo I wrote to a co-worker as a sort of post-mortem on a long-term digital preservation project. Although its in very rough form, and alludes to some things that won’t make sense to those outside of Cornell University Library, (and I tend to be pretty loose in how I deal with topics, such as the relationship between performance and scalability for example, and I assume some familiarity with certain technologies), I thought there might be enough meat hear to interest others working in the area of digital preservation.

In Rails documentation and tutorials, there are plenty of examples of how to implement binary associations, but in my searching, I have found no examples of how to implement ternary relationships, a void I hope to now fill. The key will be to make the association tables into full-fledged models and use them in has_many :through declarations to specify the relationships.