Database Ch 6 & 7 Vocab

Procedure

A collection of procedural and SQL statements that are assigned a unique name within the schema and stored in the database.

User-defined Data Type

A data type that a user can define by making it a subclass of a standard type or creating a type that behaves as an object. UDTs may also have defined functions and methods.

Relational DBMS (RDBMS)

A database management system that manages data as a collection of tables in which all data relationships are represented by common values in related tables.

Outer Join

A join in which rows that do not have matching values in common columns are nevertheless included in the result table.

Equi-join

A join in which the joining condition is based on equality between values in the common columns. Common columns appear (redundantly) in the result table.

Natural Join

A join that is the same as an equi-join except that one of the duplicate columns is eliminated in the result table.

Trigger

A named set of SQL statements that are considered (triggered) when a data modification (i.e., INSERT, UPDATE, DELETE) occurs or if certain data definitions are encountered. If a condition stated within a trigger is met, then a prescribed action is taken.

Join

A relational operation that causes two tables with a common domain to be combined into a single table or view.

Catalog

A set of schemas that, when put together, constitute a description of a database.

Scalar Aggregate

A single value returned from an SQL query that includes an aggregate function.

Function

A stored subroutine that returns one value and has only input parameters.

Schema

A structure that contains descriptions of objects created by a user, such as base tables, views, and constraints, as part of a database.

Virtual Table

A table constructed automatically as needed by a DBMS. Virtual tables are not maintained as real data.

Base Table

A table in the relational data model containing the inserted raw data. Base tables correspond to the relations that are identified in the database's conceptual schema.

Dynamic Table

A virtual table that is created dynamically upon request by a user. A dynamic view is not a temporary table. Rather, its definition is stored in the system catalog, and the contents of the view are materialized as a result of an SQL query that uses the view. It differs from a materialized view, which may be stored on a disk and refreshed at intervals or when used, depending on the RDBMS.

Data Control Language (DCL)

Commands used to control a database, including those for administering privileges and committing (saving) data.

Data Definition Language (DDL)

Commands used to define a database, including those for creating, altering, and dropping tables and establishing constraints.

Data Manipulation Language (DML)

Commands used to maintain and query a database, including those for updating, inserting, modifying, and querying data.

Materialized View

Copies or replicas of data, based on SQL queries created in the same manner as dynamic views. However, a materialized view exists as a table and thus care must be taken to keep it synchronized with its associated base tables.

Persistent Stored Modules

Extensions defined originally in SQL:1999 that include the capability to create and drop modules of code stored in the database schema across user sessions.

Embedded SQL

Hard-coded SQL statements included in a program written in another language, such as C or Java.

Correlated Subquery

In SQL, a subquery in which processing the inner query depends on data from the outer query.

Dynamic SQL

Specific SQL code generated on the fly while an application is processing.