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ACC 409 Final Exam
Chapter 4 Terms
|The specialized computer program that manages and controls thedata and interfaces between the data and the application programs.
|Database Management System (DBMS)
|The combination of the database, the database management system, and the application programs that access the database through the database management system.
|The person responsible for coordinating, controlling, and managing the data in the database.
|Very large databases that contain both detailed and summarized data for a number of years and that are used for analysis rather than transaction processing.
|Accessing information stored in a data warehouse through statistical analysis or artificial intelligence techniques to "discover" unhypothesized relationships in the data.
|A document that illustrates the arrangement of items of data input, output, and file records.
|The manner in which a user or programmer conceptually organizes, views, and understands the relationships among data items.
|The way data are physically arranged and stored in the computer system.
|A description of the types of data elements that are in the database, the relationships among the data elements, and the strucutre or overall logical model used to organize and describe the data.
|The organization-wide view of the entire database. It lists all data elements in the database and the relationships between them.
|An individual user's or application program's view of a subset of the organization's database. Each of these individual user views is also referred to as a subschema.
|(1) A subset of the schema that includes only those data items used in a particular application program or by a particular user. (2) The way the user defines the data and the data relationships.
|A low-level view of the entire database describing how the data are actually stored and accessed. It includes information about record layouts, definitions, addresses, indexes, and so forth.
|An ordered collection of data elements that contain information about the structure of the database. For each data element stored in the database, such as the customer number, there is a corresponding record in the _____ _____ describing it.
|A database management system language that ties the logical and physical views of the data together.
|Data Definition Language (DDL)
|A database management system language used for data maintenance, which includes such operations as updating, inserting, and deleting portions of the database.
|Data Manipulation Language (DML)
|A high level, English-like command language that is used to interrogate a database. Retrieves, sorts, orders, and presents subsets of the database in response to user queries.
|Data Query Language (DQL)
|A language that simplifies report creation. Searches the database, extracts the specified data items, and prints them according to the user-specified format.
|An abstract representation of teh contents of a database.
|All data elements are logically viewed as being stored in the form of two-dimensional tables called "relations". Each row represents a unique entity or record. Each column represents a field.
|Relational Data Model
|The tables used to store data in a relational database.
|A row in a relation. Contains data about a specific occurrence in a database table.
|The attribute, or combination of attributes, that uniquely identifies a specific row in a database table. Used to distinguish, order, and reference records in a database.
|An attribute appearing in one table that is itself the primary key of another table. Used to link tables.
|A problem that can arise in a poorly designed relational database. If attributes that are not characteristics of the primary key of a relation are stored in that table, then that data item is stored in many different rows.
|The problem arises because new information about those attrributes cannot be entered in the database without violating integrity rules.
|Deleting a row from that table may result in the loss of all information about those attributes that are not characteristics of the primary key.
|A database management system that uses the relational database model developed by Dr. E. F. Codd in 1970.
|A design constraint in a relational database requiring that the primary key have a non-null value. Ensures that a specific object exists in the world and can be identifited by reference to its primary key value.
|Entity Integrity Rule
|A constraint in a relational database design requiring that any non-null value of a foreign key must correspond to a primary key in the referenced table.
|Referential Integrity Rule
|The process of following the guidelines for properly designing a relational database that is free from delete, insert, and update anomalies.