Glossary

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Glossary
keyword	definition	page_link
incomplete specialization	(UML) Some members of a superclass might not be members of any subclass.	subclass.php
index	(SQL) A data structure that the database uses to find records within a table more quickly.	views.php
inner join	(SQL) Join of two tables with join attributes specified by the programmer.	jointypes.php
INSERT INTO	(SQL) Statement to add a row of data to a table.	tables.php
join (RA)	(RA) Formal definition on which the SQL join is based, the pairwise paste of tuples from the relations being joined. Please see full definition on the page.	join.php
join (SQL)	(SQL) Operation that links two tables, specified in the FROM clause of a SELECT statement. Please see full definition on the page.	join.php
join attributes	Attributes whose values are matched during the join operation.	join.php
join, cross	See cross join.	jointypes.php
join, natural	See natural join.	jointypes.php
join, non-equi-	See non-equi-join.	jointypes.php
join, outer	See outer join.	jointypes.php
join, self	See self join.	jointypes.php
junction table	(RM,TM) The table created to hold the linking attributes (FKs) from both sides of a many-to-many association.	manymany.php
key	See super key.	tables.php
key, candidate	See candidate key.	keys.php
key, external	See external key.	keys.php
key, foreign	See foreign key.	association.php
key, primary	See primary key.	tables.php
key, sub	See subkey.	subkeys.php
key, substitute	See substitute key.	keys.php
key, super	See super key.	tables.php
key, surrogate	See surrogate key.	keys.php
lossless join decomposition	Decomposition (breaking apart) of a relation scheme to eliminate a subkey. The original scheme’s information can be recreated with the join in a query.	subkeys.php
many-to-many association	(UML) An association with maximum multiplicity of ..	manymany.php
materialized view	(SQL) A view that creates and stores a result table in advance of being used.	views.php
MINUS	(RA,SQL) Operation as defined in set theory, returning the difference of the tuples/rows of two relations/tables over the same scheme.	setops.php
multiplicity	(UML) The minimum and maximum number of individuals of one class that may be associated with a single member of another class.	association.php
multivalued attribute	(UML) An attribute that contains more than one value from its domain. This is a design error.	hobbies.php
named query	(SQL) A view.	views.php
natural join	(SQL) Join of two tables with the intersection of their schemes used as join attributes.	jointypes.php
non-equi-join	(SQL) Join based on some condition other than equality of the join attributes.	jointypes.php
normal form, third	See third normal form.	subkeys.php
normal forms	(RM) A progression of rules for well-structured database design.	normalize.php
normalization	(RM) Following a set of rules to insure that a database is well designed. See also normal forms.	subkeys.php
NULL	(SQL) A special constant value, compatible with any data type, that means "this field doesn't have any value assigned to it."	phone.php

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