Glossary
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object | (UML) The instantiation of a class in OO programming languages. | class.php |
one-to-many association | (UML) An association with maximum multiplicity of 1..* | association.php |
outer join | (SQL) Join of two tables that retains unmatched join attributes from one or both sides. | jointypes.php |
overlapping specialization | (UML) Any member of a superclass may be a member of more than one subclass. | subclass.php |
parent | (RM,TM) The relation on the "one" (PK) side of a one-to-many association. | association.php |
partial FD | (RM) A subkey that is part of the primary key of a relation. | subkeys.php |
partial specialization | (UML) See incomplete specialization. | subclass.php |
paste | (RA) Tuple operation on which the RA join is based. Please see full definition on the page. | sql/join.php |
predicate | (RA) Conditional statement used in the RA select operstion. | sql/queries.php |
primary key (PK) | (RM,TM) The SK set of attributes that the designer picks as the unique identifier for a database table. | tables.php |
project (in RA) | (RA) Unary operator that picks attributes from a relation. | sql/queries.php |
property | (UML) See attribute. | class.php |
query | A request to retrieve data from the database. See SELECT (SQL). | sql/queries.php |
query, stored | See stored query. | sql/views.php |
query, sub | See subquery. | sql/subqueries.php |
recursive association | (UML) An association between a single class type (in one role) and itself (in another role). | recursive.php |
referential integrity | (RM,TM) A constraint on a table that does not allow an FK value to be entered without a matching PK value. | association.php |
relation | (RM) A set of tuples over the same scheme. | tables.php |
relational algebra (RA) | The formal language used to sympolically manipulate objects of the RM. | models.html |
relational model (RM) | The formal mathematical model of a relational database. | models.html |
relationship | (ER) See association. | association.php |
repeated attribute | (UML) An attribute that occurs more than once in the same class definition; it may also have attributes of its own. This is a design error. | phone.php |
result set | (SQL) The intermediate table that results from execution of the FROM clause of a SELECT statement. | sql/queries.php |
role | (SQL) A name for a group of database users who have been granted the same privileges. | sql/views.php |
ROLLBACK | (SQL) Statement to discard changes that have not been made permanent. | sql/ddldml.php |
row | (TM) The information about one individual in a database table. See also tuple. | tables.php |
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