Key Terms

concurrency control strategies: features of a database that allow several users access to the same data item at the same time

data type: determines the sort of data permitted in a field, for example numbers only

data uniqueness: ensures that no duplicates are entered

database constraint: a restriction that determines what is allowed to be entered or edited in a table

metadata: defines and describes the data and relationshipsbetween tables in the database

read and write privileges: the ability to both read and modify a file

read-only access: the ability to read a file but not make changes

self-describing: a database system is referred to as self-describing because it not only contains the database itself, but also metadatawhich defines and describes the data and relationships between tables in the database

view: a subset of the database