Chapter 9 - Data Design Flashcards
A type of entity relationship. A _____________________, exists when exactly one of the second entity occurs for each instance of the first entity.
1:1, one-to-one relationship
A type of entity relationship. A _______________________, exists when one occurrence of the first entity can be related to many occurrences of the second entity, but each occurrence of the second entity can be associated with only one occurrence of the first entity.
1:M, one-to-many relationship
The total number of days from some specific base date. To calculate the number of days between two ____________, subtract one date from the other. For example, using a base date of January 1, 1900, September 27, 2012, has an absolute date value of 41179 and July 13, 2011, has an absolute date of 40737. If the earlier date value is subtracted from the later one, the result is 442 days.
absolute date
Indicates what action is to be taken with an associated item. For example, a student records program might prompt a user to enter or click an action code such as D (to display the student’s record), A (to add a record), and X (to exit the program).
Action codes
Uses alphabet letters to distinguish one item from another based on a category, an abbreviation, or an easy-to-remember value.
Alphabetic codes
Stands for American Standard Code for Information Interchange, a data storage coding method used on most personal computers and workstations.
ASCII
An entity that has its own set of attributes and characteristics. _______________ are used to link between many-to-many (M:N) relationships.
associative entity
Special fields within data records to provide additional control or security information. Typical ______________ include the date the record was created or modified, the name of the user who performed the action, and the number of times the record has been accessed.
audit fields
Record details of all accesses and changes to a file or database and can be used to recover changes made since the last backup
audit log files
The process of saving a series of file or data copies to be retained for a specified period of time. Data can be __________ continuously, or at prescribed intervals.
backup
A format that offers efficient storage of numeric data. For example, when numeric data types are specified using Microsoft Access, there are a variety of storage formats choices, including integer and long integer, among others.
binary storage format
The smallest unit of data is one binary digit.
bits
Cipher that uses blocks of numbers for different classifications.
Block sequence codes
A group of eight bits is called a ____, or a character. A set of bytes forms a field, which is an individual fact about a person, a place, a thing, or an event.
byte
Sometimes it is possible to have a choice of fields or field combinations to use as the primary key. Any field that could serve as a primary key is called a _______________.
candidate key
Code that shows relationships between entities.
cardinality notation
Ciphers that identify a group of related items. For example, a local department store may use a two-character ___________ to identify the department in which a product is sold.
category codes
A group of eight bits is called a ____________. A set of bytes forms a field, which is an individual fact about a person, a place, a thing, or an event.
byte / characters
Use of a keyword to encode a number. A retail store, for example, may use a 10-letter word, such as CAMPGROUND, to code wholesale prices, where the letter C represents 1, A represents 2, and so on. Thus, the code, GRAND, would indicate that the store paid $562.90 for the item.
cipher codes
The average number of page views to accomplish a purchase or obtain desired information.
clicks to close
Recording web visitor behavior and traffic trends for later data mining. use.
clickstream storage
A set of letters or numbers that represents a data item. _____ can be used to simplify output, input, and data formats.
code
A type of data validation check that is performed on two or more fields to ensure that they are consistent or reasonable when considered together. Even though all the fields involved in a combination check might pass their individual validation checks, the combination of the field values might be inconsistent or unreasonable.
combination key
An attribute that appears in more than one entity. ________________ can be used to link entities in various types of relationships.
common field
Sometimes it is necessary for a primary key to consist of a combination of fields. In that case, the primary key is called a combination key, ______________ key, concatenated key, or multivalued key.
composite key
A type of cardinality notation. It is called _______________ because of the shapes, which include circles, bars, and symbols, that indicate various possibilities. A single bar indicates one, a double bar indicates one and only one, a circle indicates zero, and a crow’s foot indicates many.
crow’s foot notation
A _____ controls database operations, including storing, retrieving, updating, and deleting data. Most commercial DBMSs, such as Oracle and IBM’s DB2, use a _____.
data manipulation language (DML)
A specialized database designed to serve the needs of a specific department, such as sales, marketing, or finance. Each __________ includes only the data that users in that department require to perform their jobs.
data mart
Looking for meaningful patterns and relationships among data. For example, _____________ software could help a consumer products firm identify potential customers based on their prior purchases.
data mining
An integrated collection of data that can support management analysis and decision making.
data warehouse
Someone who manages a DBMS. The ___ assesses overall requirements and maintains the database for the benefit of the entire organization rather than a single department or user.
database administrator (DBA)
