The problems inherent in file systems make using a database system very desirable. Unlike the file system, with its
many separate and unrelated files, the database system consists of logically related data stored in a single logical data
repository. (The “logical” label reflects the fact that the data repository appears to be a single unit to the end user, even
though data might be physically distributed among multiple storage facilities and locations.) Because the database’s
data repository is a single logical unit, the database represents a major change in the way end-user data are stored,
accessed, and managed. The database’s DBMS, shown in Figure 1.8, provides numerous advantages over file system
management, shown in Figure 1.7, by making it possible to eliminate most of the file system’s data inconsistency, data
anomaly, data dependence, and structural dependence problems. Better yet, the current generation of DBMS software
stores not only the data structures, but also the relationships between those structures and the access paths to those
structures—all in a central location. The current generation of DBMS software also takes care of defining, storing, and
managing all required access paths to those components.
The problems inherent in file systems make using a database system very desirable. Unlike the file system, with its
many separate and unrelated files, the database system consists of logically related data stored in a single logical data
repository. (The “logical” label reflects the fact that the data repository appears to be a single unit to the end user, even
though data might be physically distributed among multiple storage facilities and locations.) Because the database’s
data repository is a single logical unit, the database represents a major change in the way end-user data are stored,
accessed, and managed. The database’s DBMS, shown in Figure 1.8, provides numerous advantages over file system
management, shown in Figure 1.7, by making it possible to eliminate most of the file system’s data inconsistency, data
anomaly, data dependence, and structural dependence problems. Better yet, the current generation of DBMS software
stores not only the data structures, but also the relationships between those structures and the access paths to those
structures—all in a central location. The current generation of DBMS software also takes care of defining, storing, and
managing all required access paths to those components.
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