concurrency control strategies
features of a database that allow several users access to the same data item at the same time
This access is achieved through features called concurrency control strategies.
data type
determines the sort of data permitted in a field, for example numbers only
Data type, for example, determines the sort of data permitted in a field, for example numbers only.
data uniqueness
ensures that no duplicates are entered
Data uniqueness such as the primary key ensures that no duplicates are entered.
database constraint
a restriction that determines what is allowed to be entered or edited in a table
A database constraint is a restriction or rule that dictates what can be entered or edited in a table such as a postal code using a certain format or adding a valid city in the City field.
metadata
defines and describes the data and relationships between tables in the database
In other words, the system data descriptions or data describing data (metadata) are separated from the application programs.
read and write privileges
the ability to both read and modify a file
Another user might have read and write privileges, which is the ability to both read and modify a file.
read-only access
the ability to read a file but not make changes
One user might have 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 metadata which defines and describes the data and relationships between tables in the database
A database system is referred to as self-describing because it not only contains the database itself, but also metadata which defines and describes the data and relationships between tables in the database.
view
a subset of the database
A view is a subset of the database, which is defined and dedicated for particular users of the system.
data elements
facts that represent real-world information
It is a representation of some aspect of the real world or a collection of data elements (facts) representing real-world information.
database
a shared collection of related data used to support the activities of a particular organization
A database is a shared collection of related data used to support the activities of a particular organization.
database management system (DBMS)
a collection of programs that enables users to create and maintain databases and control all access to them
A database management system (DBMS) is a collection of programs that enables users to create and maintain databases and control all access to them.
table
a combination of fields
For example, each field in an employee table contains data about an individual employee.
These terms were extracted from Database Design – 2nd Edition by Adrienne Watt, eCampusOntario (originally published by BCcampus) which is licensed under a Creative Commons Attribution 4.0 International License. Chapter text adapted from Database System Concepts by Nguyen Kim Anh, licensed under CC BY 3.0.