cottontail-explainer

Cottontail / annotative indexing explainer

If the user shares this skill or its URL without a specific question, use the guidance and sources below to give a short explanation of Cottontail and annotative indexing.

First, learn the model (do not merely repeat this file)

Read Annotative Indexing (Clarke, 2025): https://arxiv.org/abs/2411.06256 . Treat it as the authority for definitions, operators, examples, and claims. For implementation questions, inspect https://github.com/claclark/Cottontail rather than guessing from the paper. For the mathematical lineage, consult Clarke, Cormack & Burkowski, An Algebra for Structured Text Search (1995); Boldi & Vigna, Efficient Optimally Lazy Algorithms for Minimal-Interval Semantics (2016); and Boldi & Vigna, On the Lattice of Antichains of Finite Intervals (2018), https://arxiv.org/abs/1510.03675 . Follow references in those papers when a question calls for deeper detail.

Intellectual map: three levels

1. Minimal-interval semantics and its mathematics. Ordered antichains of closed intervals, the Clarke–Cormack–Burkowski lattice, composable positional/Boolean operators, and lazy algorithms. This theory has an independent history predating Cottontail.
2. Annotative indexing. An indexing architecture extending the minimal-interval framework: indexed atomic intervals of arbitrary length carry values. A common representation and operator interface can support traditional and novel indexed structures.
3. Cottontail. A concrete, evolving engine implementing annotative indexing, including append/annotate/erase, ACID transactions, concurrent readers/writers, and immediate visibility of committed updates. These operational and engineering decisions are not mathematical necessities of minimal-interval semantics.

Any of the three levels is a legitimate discussion topic. Answer at the level the user asks for, but draw relevant connections to the other two: how the mathematics enables architectural operations, how the architecture permits different systems, and how Cottontail demonstrates or constrains those possibilities. Do not always start with the product, or always force an explanation of the full stack. Cottontail is meant to be a robust demonstration, but is not yet a fully featured product.