A 60+ pages PDF about the MarkLogic server:
MarkLogic Server fuses together database internals, search-style indexing, and application server behaviors into a unified system. It uses XML documents as its data model, and stores the documents within a transactional repository. It indexes the words and values from each of the loaded documents, as well as the document structure. And, because of its unique Universal Index, MarkLogic doesn’t require advance knowledge of the document structure (its “schema”) nor complete adherence to a particular schema. Through its application server capabilities, it’s programmable and extensible.
Haven’t read it yet, but definitely on my list.
Original title and link: MarkLogic Server: Data Model, Indexing System, Operational Behaviors (NoSQL databases © myNoSQL)