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A.6 Formal System Identifier Definition
Requirements (FSIDR)
The most common storage managers are the file systems of operating systems and networks. These have the property that the objects stored by them are not stored within some other object. In contrast, several storage managers, such as archivers and data base managers, store objects within a larger object. Typically, those objects (the "archives" or "data bases") are stored as files by a file system, although in some cases they could be stored within a larger archive or data base.
In the context of formal system identifiers, storage managers that store objects within larger objects are known as "container storage managers". The notation for a container storage manager's SOI is known as a "container notation", derived from the FSIDR container notation form.
A container is an entity whose storage is partitioned so that the bodies of other entities ("contained objects") can be kept in it. The locations of the contained objects are specified by their entity declarations. The entity declarations serve as entries in a "table of contents" or "directory" of the container.
NOTE 500 Container entities provide a storage organization that applications may take advantage of to avoid redundant descriptor information. Containers may also facilitate interleaving and other techniques that optimize access to multimedia data.
When a container SM is used, the characters of the container entity are treated as the storage octets of the contained entities.
NOTE 501 When a query language (such as SQL or SDQL) is used as a storage manager notation, only queries that return a single storage object are valid. In the usual case, the query language will be a container notation, with the container entity being the relational table or other query domain and the SOI of the contained entity being the query.
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