Term
|
Definition
| Collection of interrelated data items that are managed as a single unit. |
|
|
Term
|
Definition
| A copy of the database software running in memory. Multiple databases are typically managed by a single instance. |
|
|
Term
|
Definition
| A named data structure that is stored in a database. Database objects vary from one database model to another. |
|
|
Term
|
Definition
| The way in which a database organizes its data to pattern the real world. |
|
|
Term
|
Definition
| A collection of related records that are stored as a single unit by an operating system. |
|
|
Term
| Database Management System (DBMS) |
|
Definition
| Software provided by the database vendor. Examples are Microsoft Access and Oracle. |
|
|
Term
|
Definition
| A system of commands that a database user employs to retrieve data from the database. |
|
|
Term
|
Definition
| Presenting multiple users of the data with their own distinct views of the data while storing the underlying data only once. |
|
|
Term
|
Definition
| A set of computer programs designed to solve a particular business problem, such as payroll-processing system. |
|
|
Term
|
Definition
| Each user can have a view of the same data, but the views can be tailored to the needs of the individual users. |
|
|
Term
|
Definition
| Views automatically reflect any data changes made to the underlying database objects. |
|
|
Term
|
Definition
| Contains the data files that hold all the data for the database. Deals with storage |
|
|
Term
|
Definition
| A layer of abstraction in the database assembled from the physical layer as needed. Once the schema is established data can be inserted, updated, deleted, and queried. |
|
|
Term
|
Definition
| Second layer of abstraction in the database. Composed of subschema. The layer where users and application programs that access the database connect and issue queries against the database. |
|
|
Term
| Database Administrator (DBA) |
|
Definition
| technician that handles the details of installing and configuring the database software and data files. Deals with the physical and logical layers. |
|
|
Term
|
Definition
| The collection of all the data items stored in a particular database. |
|
|
Term
|
Definition
| The collective user views. |
|
|
Term
|
Definition
| A query that was not preconceived and one that is not likely to be reused. |
|
|
Term
| Physical data independence |
|
Definition
| The ability to alter the physical file structure of a database without disrupting existing users and processes. |
|
|
Term
|
Definition
| How much change can be made in the file system without impacting the logical layer. |
|
|
Term
|
Definition
| Keeps track of where the objects are physically stored. |
|
|
Term
| Logical Data Independence |
|
Definition
| The ability to make changes to the logical layer without disrupting existing users and processes. Most logical changes also involve a physical change. Example: you cannot add a new database object without physically storing the data somewhere. |
|
|
Term
|
Definition
| The architecture that the DBMS uses to store objects within the database and relate them to one another. |
|
|
Term
|
Definition
| "Ordinary" operating system files. Records in the file contain no information to communicate the file structure or any relationship among the records. Existed before databases. |
|
|
Term
|
Definition
| A unit of computer program logic that performs a particular function within an application system. |
|
|
Term
|
Definition
| Each file from the flat file system. Connected using pointers |
|
|
Term
|
Definition
| Tell the computer system where the related record was physically located. Similar to a street address directing us to a particular building. |
|
|
Term
|
Definition
| Each pointer establishes a parent-child relationship. One parent may have many children, but each child may have only one parent. |
|
|
Term
|
Definition
| Evolved around the same time as the hierarchical database model. Record types depict what would be separate files in a flat file system, and those records are related using owner-member relationships. Greater flexibility but greater complexity. |
|
|
Term
| Owner-member relationships/ sets |
|
Definition
| One-to-many or parent and child relationships. |
|
|
Term
|
Definition
| Based on the notion that any preconceived path through a data structure is too restrictive a solution. Provides the ability to relate records as needed. |
|
|
Term
|
Definition
| Combining tables to form views. A common data item is stored in each table. |
|
|
Term
| Entity Relationship Diagram (ERD) |
|
Definition
| Diagram in which lines are drawn between tables to show one-to-many relationships. |
|
|
Term
| Object-Oriented Model (OO) |
|
Definition
| A model that allows mainstream delivery of complex data. |
|
|
Term
|
Definition
| Relational Database Management Systems |
|
|
Term
|
Definition
| A logical grouping of related data and program logic that represents a real world thing. |
|
|
Term
|
Definition
| Individual data items such as customer ID or customer name. |
|
|
Term
|
Definition
| A piece of application program logic that operates on a particular object and provides a finite function. Example: checking a customer's credit limit or updating a customer's address. |
|
|
Term
|
Definition
| Variables may only be accessed through methods. |
|
|
Term
|
Definition
| A copy of the object structure |
|
|
Term
|
Definition
| A way objects are organized so that the common methods and variable definitions need only be defined once. |
|
|
Term
|
Definition
| Methods and variable definitions shared with members of the same class. |
|
|
Term
| Object-relationship Model/Universal database |
|
Definition
| Combination of the OO model and relational DBMS products. "Best of both models" |
|
|
Term
|
Definition
| A new discipline in mathematics. |
|
|
