Term
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Definition
| a set of interrelated, centrally located files |
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Term
Database management system
(DBMS) |
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Definition
| the interface between the database and the various application programs |
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Term
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Definition
| the database, the DBMS (database management system), and the application programs that access that database through DBMS |
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Term
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Definition
| person responible for the database |
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Term
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Definition
| contains both detailed and summarized data for a number of years and is used for analysis rather than transaction processing; not unusual to contain hundreds of terabytes of data |
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Term
transcation processing system
vs
data warehouse |
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Definition
data warehouses do not replace transaction processing systems; they complement them by providing support for strategic decision making
data warehouses are usually updated periodically, whereas transaction processing systems are usually update in real-time |
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Term
business intelligence
(two main techniques used?) |
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Definition
using a data warehouse for strategic decision making:
1: online analytical processing (OLAP)
2: data mining |
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Term
| Online analytical processing (OLAP) |
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Definition
| use of queries to guide the investigation of hypothesized relationships in data |
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Term
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Definition
| using sophisticated statistical analysis, including artificial intelligence techniques such as neural networks, to "discover" unhypothesized relationships in the data |
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Term
| Advantages of database systems |
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Definition
- data integration
- data sharing
- reporting flexibility
- minimal data redundancy and inconsistencies
- data independence
- central management of data
- cross-functional analysis
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Term
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Definition
| master files are combined into large "pools" of data that many application programs access. |
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Term
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Definition
| integrated data are more easily shared with authorized users. Databases are easily browsed to research a problem or obtain detailed information underlying a report |
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Term
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Definition
| because data and the programs that use them are independent of each other, each can be changed without changing the other. This facilitates programming and simplifies data management |
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Term
| cross-functional analysis |
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Definition
| in a database system, relationships, such as the association between selling costs and promotional campaigns, can be explicitly defined and used in the preparation of management reports |
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Term
| Logical view of data vs. physical view |
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Definition
| the logical view is how people conceptually organized and understand the data; the physical view refers to how and where data are physically arranged and stored in the computer system |
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Term
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Definition
a schema describes the logical structure of a database. there are three levels of schemas:
the conceptual
the external
the internal |
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Term
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Definition
| the organization wide view of the entire database, lists all data elements and the relationships among them |
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Term
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Definition
| consists of individual user views of portions of the database, each of which is referred to as a subschema |
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Term
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Definition
| a low-level view of the database, describes how the data are stored and accessed, including record layouts, definitions, addresses, and indexes |
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Term
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Definition
| contains information about the structure of the database |
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Term
Several Languages of a DBMS
(functions of each language) |
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Definition
-
data definition language (DDL): builds the data dictionary, creates the database, describes logical views for each user, and specifies records or field security constraints
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data manipulation language (DML): changes database content, including data element updates, insertions, and deletions
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data query language (DQL): contains powerful, easy-to-use commands that enable users to retrieve, sort, order, and display data
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Term
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Definition
| the abstract representation of database contents, upon which the DBMS is based |
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Term
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Definition
| each row in a table containing data about a specific occurrence of the type of entity represented by that table. |
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Term
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Definition
| the database attribute, or combination of attributes, that uniquely identifies a specific row in a table |
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Term
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Definition
| an attribute, that is a primary key in another table, used to link tables |
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Term
| Four basic requirements of a relational database |
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Definition
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every column in a row must be single valued (one value per field, per row)
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primary keys cannot be null (blank)
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Foreign keys, if not null (blank), must have values that correspond to the value of a primary key in another table
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all nonkey attributes in a table must describe a characteristic of the object identified by the primary key
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Term
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Definition
| no customer data can be recorded until a sales transaction is made because all of the data is stored in one table and new records are created when a sale takes place |
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Term
| Referential integrity rule |
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Definition
| a foreign key must either by null or correspond to the value of a primary key in another table |
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Term
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Definition
| an approach to designing a database that assumes everything is initally stored in one large table. Rules are then followed to decompose that initial table into a set of tables called third normalization form 3NF, at which point they are free of update, insert, and delete anomalies |
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Term
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Definition
| a database design approach where the designer uses knowledge of business processes and information needs to create a diagram that shows what to include in the database. This diagram is used to create a set of relational tables that are already in 3NF form. |
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Term
Direct Access Storage Device (DASD) - Hard Drive:
component characteristics |
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Definition
- disks - multiple platters on each unit with storage on top and bottom
- read/write heads - for each side of each platter
- tracks - concentric rings on each disk
- sectors - 512 bytes of data on a track
- clusters - groups of sectors that store files
- cylinders - the vertical dimension of all tracks through all platters
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Term
| Types of Database Systems |
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Definition
Hierarchical
relational
object oriented
all are used. hierarchical is still efficient for large volumes of transactions where there are no queries or changes to the processing |
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Term
DML Example (Using SQL)
structured query language |
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Definition
SELECT *
FROM personal_info
WHERE salary > 50000
UPDATE personal_info
SET salary = salary + 5000
WHERE employee_id = 12345
INSERY INTO personal_info
values('bart','simpson',12345,45000) |
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Term
The relational data model portrays data as being stored in ________.
a) hierarchies
b) tables
c) objects
d) files |
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Definition
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Term
How a user conceptually organizes and understands data is referred to as the ________.
a) physical view
b) logical view
c) data model view
d) data organization view |
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Definition
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Term
What is each row in a relational database table called?
a) relation
b) attribute
c) anomaly
d) tuple |
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Definition
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Term
Which of the following is an individual user's view of the database?
a) conceptual-level view
b) external-level view
c) internal-level schema
d) logical-level schema |
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Definition
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Term
Which of the following would managers most likely use to retrieve information about sales during the month of October?
a) DML
b) DSL
c) DDL
d) DQL |
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Definition
| d) DQL (data query language) |
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Term
Which of the following attributes would most likely be a primary key?
a) supplier name
b) supplier number
c) supplier Zip Code
d) supplier account balance |
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Definition
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Term
Which of the following is a software program that runs a database system?
a) DQL
b) DBMS
c) DML
d) DDL |
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Definition
| b) DBMS (database management system) |
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Term
The constraint that all primary keys must have non-null data values is referred to as which of the following?
a) referential integrity rule
b) entity integrity rule
c) normalization rule
d) relational data model rule |
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Definition
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Term
The constraint that all foreign keys must have either null values or the value of a primary key in another table is referred to as which of the following?
a) referential integrity rule
b) entity integrity rule
c) foreign key value rule
d) null value rule |
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Definition
| a) referential integrity rule |
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Term
Which of the following attributes in the Cash receipts table (representing payments received from customers) would most likely be a foreign key?
a) cash receipt number
b) customer check number
c) customer number
d) cash receipt date |
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Definition
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