Figure 3

Data organization of the local repository maintained by openBEB. Data are organized hierarchically in collections. The uppermost level (root collection) is called a bundle. Bundles contain collections, and collections can contain other collections: The collection root is denoted collectionName.bundle, where collectionName is the bundle name. A bundle defines the file system location (file-system path) where the collection hierarchy is stored. A collection contains four folders: Folder one, RawData, contains the raw-data. The raw data is never changed by openBEB, however, openBEB calculates an MD5 check sum to monitor the data integrity and allows data compression by a lossless algorithm. Folder two, Annotations, contains metadata information, preview and graphically annotated representations of the data. It also contains the embedded metadata of the raw files in a standardized xml format. Folder three, Cache, contains cache information. This information stores cache files for faster browsing or stores processing results. All of the cache information is redundant and can be recalculated at any time from the information contained in folders one and two. Consequently, the information in the cache folder is not synchronized with the database. Folder four, Collections, is a container hosting sub-collections, allowing an arbitrary hierarchical, tree-like structure of collections to be built.