1. In a computing environment comprising a processor operatively coupled to a memory, a computer-implemented method for facilitating transaction-based access to unstructured data stored in a file system by managing access to the unstructured data with a database engine, the method comprising: provisioning a subset of a file system that is configured to store and manage unstructured data with one or more claim ownership blocks (COBs), the one or more COBs providing access to unstructured data stored as one or more file streams within the subset of the file system via one or more handles corresponding to the one or more file streams; associating the one or more COBs with a database engine that is configured to store and manage structured data structured according to a data model, the one or more COBs providing the database engine access to the unstructured data; exporting to one or more clients a set of entry points into the subset of the file system, thereby enabling local and remote access to the unstructured data corresponding to the one or more COBs via at least one share that leads into a namespace of the database engine; the database engine creating a transaction instance that facilitates transaction-based access to the unstructured data stored within the subset of the file system; associating at least one handle of the one or more handles and a corresponding file stream with the transaction instance; and managing the at least one handle based at least in part on a state of the associated transaction instance to provide transactional guarantees to the corresponding file stream, the transactional guarantees including atomicity and isolation of the at least one file stream among the one or more clients.