Glossary
[ Skip navigation ] Show: [ all keywords ] [ A–C ] [ D–H ] [ I–N ] [ O–R ] [ S–Z ]
| keyword | definition | page_link |
|---|---|---|
| scheme | (RM) A set of attributes, with an assignment rule. | class.php |
| select (in RA) | (RA) Unary operator that picks tuples from a relation. | queries.php |
| SELECT (in SQL) | (SQL) Statement used to retrieve data from a table. | queries.php |
| self join | (SQL) Join of one table to itself. | jointypes.php |
| specialization | (UML) (noun) A subclass. (verb) The process of designing subclasses from "top down." | subclass.php |
| specialization constraints | (UML) Description of subclass membership (incomplete versus complete, disjoint versus overlapping). | subclass.php |
| specialization, complete | See complete specialization. | subclass.php |
| specialization, disjoint | See disjoint specialization. | subclass.php |
| specialization, exclusive | See disjoint specialization. | subclass.php |
| specialization, incomplete | See incomplete specialization. | subclass.php |
| specialization, overlapping | See overlapping specialization. | subclass.php |
| specialization, partial | See incomplete specialization. | subclass.php |
| stereotype | (UML) A designator before a class name that specifies the type of the class. | enum.php |
| stored query | (SQL) A view. | views.php |
| structured query language (SQL) | The language used to build and manipulate relational databases. | models.html |
| subclass | (UML) A class that inherits common attributes from a parent class, but contains unique attributes of its own. See also superclass and specialization. | subclass.php |
| subkey | (RM) A set of attributes that is a super key for some, but not all, of the attributes in a relation. | subkeys.php |
| subquery | (SQL) A query (SELECT statement) that is embedded in another query. | subqueries.php |
| subscheme | (RA) A subset of the attributes in a scheme, preserving the assignment rule. Used in the RA project operation. | queries.php |
| substitute PK | (RM) An artificial, somewhat meaningful, primary key made up by the database designer under certain limited conditions. See also surrogate PK. | keys.php |
| SUM | (SQL) Aggregate function to sum the values in a column. | functions.php |
| super key (SK) | (RM,TM) Any set of attributes whose values, taken together, uniquely identify each row of a table. | tables.php |
| superclass | (UML) A class that contains attributes common to one or more child classes. See also subclass and generalization. | subclass.php |
| surrogate PK | (RM) An artificial, meaningless, primary key made up by the database designer under certain limited conditions. See also substitute PK. | keys.php |
| table | (TM) A set of rows. See also relation. | tables.php |
| table model (TM) | An informal set of terms for RM objects. | models.html |
| third normal form (3NF) | (RM) A database with no subkey in any relation (with rare exceptions). See also normal forms. | subkeys.php |
| transitive FD | (RM) A subkey that is not part of the primary key of a relation. | subkeys.php |
| tuple | (RM) A function that assigns a constant value from the attribute domain to each attribute in a relation scheme. | tables.php |
| unified modeling language (UML) | An enterprise modeling tool used in database design and software engineering. | models.html |
| UNION | (RA,SQL) Operation as defined in set theory, returning the union of the tuples/rows of two relations/tables over the same scheme. | setops.php |
| UPDATE | (SQL) Statement to change existing data in a table. | tables.php |
| validation rule | (TM) An algorithm or procedure to separate good from bad data. | domains.php |
| view | (SQL) Any SELECT query that has been given a name and saved in the database. | views.php |
| view, materialized | See materialized view. | views.php |
| weak entity | (ER) An entity (UML class) type that can't exist without its parent entity type. | phone.php |
[ Skip navigation ] Show: [ all keywords ] [ A–C ] [ D–H ] [ I–N ] [ O–R ] [ S–Z ]
Copyright © 2002–2006, by Tom Jewett. Links to this site are welcome and encouraged. Individual copies may be printed for non-commercial classroom or personal use; however, this material may not be reposted to other web sites or newsgroups, or included in any printed or electronic publication, whether modified or not, without specific permission from the author.