Galois Tech Talk: Databases are Categories 2: Refinements and Extensions.
presenter: David Spivak
About five months ago I gave a talk here at Galois called “Databases are categories.” The basic idea was that a database schema can be represented as a category C and its states can be represented as functors C–>Set. In this talk I’ll refine that notion a bit, explaining that schemas are better represented as sketches. I’ll also show how, within this model one can: deal with incomplete data; incorporate typing and calculated fields; and perform queries, define views, and migrate data between disparate schemas. That is, I’ll try to show that the categorical approach handles everything one might hope it would. Finally, I’ll discuss a linguistic version of categories, called “ologs,” and show how they may help to democratize information storage.