Glossary of DBMS

Attribute
An attribute is a named column of a relation. Relation
A relation is a table with columns and rows. Cardinality
The cardinality of a relation is the number of tuples it contains. File-based System
A collection of application programs that perform services for the end-users such as the production
of reports. Each program defines and manages its own data. Database
A shared collection of logically related data (and a description of this data), designed to meet the
information needs of an organization. DBMS
A software system that enables users to define, create, and maintain the database and provides
controlled access to this database. Relation Database
A collection of normalized relations. Degree
The degree of a relation is the number of attributes it contains. Domain
A domain is the set of allowable values for one or more attributes. Reserved words
A reserved word in SQL is a word that has a specific meaning to SQL, such as SELECT, FROM,
TABLE, etc. By convention, these are written in capital letters. User-defined words
A user-defined word in SQL is a word that the user has chosen to name tables, columns, and other
variables. Literals
A literal in SQL is a string. That is, a set of characters (case-sensitive) that makes up a
non-numeric piece
of information, written exactly as it is written in the database. Literals are enclosed in single
quotes in SQL. Column Identifier
A column identifier may be either a colum name or a column number that identifies an element of the
SELECT list by its position within the list, 1 being the first (left-most) element in the list, 2 the
second element in the list, and so on. Nested Query
Nested query is when a SELECT statement embedded within another SELECT statement. Scalar Nested Query
Scalar nested query returns a single column and a single row; that is, a single value. Row Nested Query
Row nested query returns multiple columns, but again only a single row. Table Nested Query
Table nested query returns one or more columns and multiple row. Tuple
A tuple is a row of a relation.