Atomic Transactions : In Concurrent and Distributed Systems (Morgan Kaufmann Series in Data Management Systems)

The book provides a formal mathematical model that attempts to explain the behaviors of OLTP systems at several levels, much as the equations that we use to explain gravity work at both the atomic and the planetary levels. The model, which is extremely complicated and contains loads of mathematical notation, explains how time, data, and user behavior interact to form a system that allows concurrent access to a database.

If you don't already have a good understanding of what goes on in an OLTP system, this isn't the book to read. Rather, take a look at Transaction Processing: Concepts and Techniques by Jim Gray and Andreas Reuter.