Biomedical Engineering Reference
In-Depth Information
Definitions
Databases, which provide the long-term memory of computer operations, take on a variety of names,
depending on their structure, contents, use, and amount of data they contain. Two technologies often
confused with databases are disk servers and file servers. A disk server is a node in a local area
network that acts as a remote disk drive. A disk server can be divided into multiple volumes, some of
which are shared by all users on the server, and others of which can be accessed only by a specific
user, as defined by username and password login. At the next level in sophistication is the file server,
which can be thought of as a disk server with intelligence. A file server not only stores files, but
manages the network requests for them and maintains order as users request and modify files.
The file server, like the disk server, supports movement and cataloging of files, but, unlike a true
database, the contents of a file server are unavailable without the use of some other application.
With both disk servers and file servers, separate applications must be used to open documents for
reviewing and editing. In this regard, most disk and file servers work like extensions to the computer
operating system. Files can be identified, copied, deleted, and otherwise managed at a very high
level. For our purposes, file servers and disk servers can be considered as extensions to the internal
workstation hard drive that may be configured as a shared volume so that collaborators on the same
network can share data stored on the server.
At the simplest level of a true database is the data repository, a database used as an information
storage facility, with minimal analysis or querying functionality. A data repository is a structured,
systematically collected storehouse of data distilled or mirrored from a single application, such as a
sequencing machine, microarray analyzer, or clinical system (see Figure 2-1 ).
Figure 2-1. Database Nomenclature. Data repositories, data marts, and data
warehouses differ primarily in the diversity of data sources that contribute
to their contents.
 
 
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