Final Exam Prep Flashcards
What is stored representations of objects and events that have meaning and importance in the user’s environment?
Data
What is data that have been processed in such a way as to increase the knowledge of the person who uses the data?
Information
What is data that describes the properties or characteristics of end-user data and the context of those data?
Metadata
Why were computer based file processing systems developed?
To store, manipulate, and retrieve large files of data.
What are some disadvantages associated with file processing?
- Program-data dependence
- Duplication of data
- Limited data sharing
- Lengthy development times
- Excessive Program Maintenance
What are graphical systems used to capture the nature and relationships among data?
Data model
What is an applicaiton program (or set or related programs) that is used to perform a series of database activities (create, read, update, and delete) on behalf of database users.
Database application
What is a person, a place, an object, an event, or a concept in the user environment about which the organization wishes to maintain data?
An entity
What is a database that represents data as a collection of tables in which all data relationships are represented by common values in related tables?
Relational Database
What is a software system that is used to create, maintain, and provide controlled access to user databases?
Database Management System (DBMS)
What are advantages of the Database approach?
- Program-data independence
- Planned data redundancy
- Improved data consistency
- Improved data sharing
- Increased productivity of application development
- Enforcement of standards
- Improved data quality
- Improved data accessibility and responsiveness
- Reduced program maintenance
- Improved decision support
What is the seperation of data descriptions from the application programs that use the data?
Data independence
What are software tools that provide automated support for creating data models?
Data modeling and design tools?
What are the components of the database environment?
- Data modeling and desing tools
- Repository
- DBMS
- Database
- Application programs
- User interface
- Data and database administrators
- System developers
- End users
What is a centralized knowledge base of all data definitions, data relationships, screen and report formats, and other system components?
Repository
What is the first step in database development, in which the scope and general contents of organizational databases are specified?
Enterprise data modeling
What is the traditional methodology used to develop, maintain, and replace information systems?
Systems Development Life Cycle (SDLC)
What are the parts of the SDLC?
- Planning - Enterprise modeling
- Planning - Conceptual data modeling
- Analysis - Conceptual Data Modeling
- Design - Logical database design
- Design - Physical database design and definition
- Implementation - Database implementation
What is the purpose of the SDLC?
To develop a preliminary understanding of a business situation and how information systems might help solve a problem or make an oppurtunity possible.
What is a detailed, technology-independent specification of the overall structure of organizational data?
Conceptual schema
What is the representation of a database for a particular data management technology?
Logical schema
What are specifications for how data from a logical schema are stored in a computer’s secondary memory by a DBMS?
Physical schema
What is an iterative process of systems development in which requirements are converted to a working system that is continually revised through close work between analysts and users?
Prototyping
What is an approach to database and software development that emphasizes “individuals and interactions over process and tools, working software over comprehensive documentation, customer collaboration over contract negotiation, and response to change over following a plan.”?
Agile software development
What is a planned undertaking of related activities to reach an objective that has a beginning and an end?
Project
What is a business management system that integrates all functions of the enterprise, such as manufacturing, sales, finance, marketing, inventory, accounting, and human resources?
Enterprise Resource Planning (ERP) Systems
What systems are software applications that provide the data necessary for the enterprise to examine and manage it’s activities?
Enterprise resource planning (ERP) systems
What is an integrated decision support database whose content is derived from the various operational databases?
Data warehouse
What is a logical representation of the data for an organization or for a business area, using entities for categories of data and relationships for associations between entities.
Entity-Relationship Model (E-R Model)
What is a graphical representation of an entity-relationship model?
Entity-Relationship diagram (ERD)
What are the cardinalities in an ERD?
- Two lines across the relationship line = Mandatory one relationship
- One line with a Forked end = Mandatory many relationship
- One circle with one line = Optional one relationship
- One circle with forked end = Optional many relationship
What is a statement that defines or constrains some aspect of the business. It is intended to assert business structure or to control or influence the behavior of the business.
Business rules
What are the characteristics of a good business rule?
- Declarative
- Precise
- Atomic
- Consistent
- Expressible
- Distinct
- Business-oriented
What is a word or phrase that has a specific meaning for the business?
Term
What is an association between two or more terms?
Fact
What is a person, place, an object, an event, or a concept in the user environment about which the organization wishes to maintain data?
Entity
What is a collection of entities that share common properties or characteristics?
Entity type
What is a single occurence of an entity type?
Entity instance
What is an entity that exists independently of other entity types?
Strong entity type
What is an entity type whose existence depends on some other entity type?
Weak entity type
What is the entity type on which teh weak entity type depends?
Identifying owner
What is the relationship between a weak entity type and its owner?
Identifying relationship
What is a property or characteristic of an entity or relationship type that is of interest to the organization?
Attribute
What is an attribute that must have a value for every entity (or relationship) instance with which it is associated?
Required attribute
What is an attribute that may not have a value for every entity (or relationship) instance with which it is associated?
Optional attribute
What is an attribute that has meaningful component parts(attributes)?
Composite attribute
What is an attribute that cannot be broken down into smaller components that are meaningful to the organization?
Simple (or atomic) attribute
What is an attribute that may take on more than one value for a given entity (or relationship) instance?
Multivalued attribute
What is an attribute whose values can be calculated from related attribute values?
Derived attribute
What is an attribute (or combination of attributes) whose value distinguishes instances of an entity type?
Identifier
What is an identifier that consist of a composite attribute?
Composite identifier
How are composite attributes identified in an Entity?
No special annotation
How are component attributes identified in an entity?
Inside () and below the attribute they are component to
How are multivalued attributes identified in an Entity?
Inside curly braces { }
How are multivalued attributes displayed in an entity?
Inside square [] brackets.
How are identifiers displayed in an Entity?
Underlined, think IDs StudentID etc.
What is a meaningful association between (or among) entity types?
Relationship type
What is an association between (or among) entity instances where each relationship instance associates exactly one entity instance from each participating entity type?
Relationship instance
What is an entity type that associates the instances of one or more entity types and contains attributes that are peculiar to the relationship between those entity instances?
Associate entity
What is the number of entity types that participate in a relationship?
Degree
What is a relationship between instances of a single entity type?
Unary relationship
What is a relationship between the instances of two entity types?
Binary relationship
What is a simultaneous relationship among the instances of three entity types?
Ternary relationship
What is a rule that specifies the number of instances of one entity that can (or must) be associated with each instance of another entity?
Cardinality constraint
(Think the lines and cirles on the relationship line, they control how many can go into the entity)
i.e: double lines = minimum of one and maximum of one
circle line means minimun of zero and max of one
line fork - min one max many
circle fork - min zero max many
What is the minimum number of instances of one entity that may be associated with each instance of another entity?
Minimum cardinality
What is the maximum number of instances of one entity that may be associated with each instance of another entity?
Maximum cardinality
What is a time value that is associated with a data value, often indicating when some event occured that affected the data value?
Time stamp
What is a named two-dimensional table of data?
A relation
What is an attribute or a combination of attributes that uniquely identifies each row in a relation?
Primary key
What is a primary key that consists of more than one attribute?
Composite key
What is an attribute in a relation that serves as the primary key of another relation in the same database?
Foreign key
What are the three major types of integrity constraints?
- Domain Constraints
- Entity Integrity
- Referential Integrity
What constraint means that all values that appear in a column of a relation must be from the same domain?
Domain constraints
What is the set of values that may be assigned to an attribute?
A domain
What are the components of a domain definition?
- Domain name
- Meaning
- Data type
- Size (or length)
- Allowable values or allowable range (if applicable)
Which integrity rule is designed to ensure that every relation has a primary key and that the data values for that primary key are all valid?
Entity Integrity
What is a value that may be assigned to an attribute when no other value applies or when the applicable value is unknown?
Null
What is a rule that states that no primary key attribute (or component of a primary key attribute) may be null?
Entity integrity rule
What is a rule that states that either each foreign key value must match a primary key value in another relation or the foreign key value must be null?
Referential integrity constraint
What is a relation that contains minimal redundancy and allows users to insert, modify, and delete the rows in a table without errors or inconsistencies?
Well-structured relation
What is an error or inconsistency that may result when a user attempts to update a table that contains redundant data.
Anomaly
What are the three types of anomalies?
Insertion, deletion, and modification
What is a serial number or other system-assigned primary key for a relation?
Surrogate Primary key
What is a foreign key in a relation that references the primary key values of the same relation?
Recursive foreign key
Like in a unary relationship
What is the process of decomposing relations with anomalies to produce smaller, well-structured relations.
Normalization
What are the goals of normalization?
- Minimize data redundancy, thereby avoiding anomalies and conserving storage space.
- Simplify the enforcement of referential integrity constraints
- Make it easier to maintain data (insert, update, delete)
- Provide a better design that is an improved representation of the real world and a stonger basis for future growth
What is a state of a relation that requires that certain rules regarding relationships between attributes (or functional dependencies) are satisfied?
Normal Form
What are the steps in normalization?
- First normal form
- Second Normal form
- Third normal form
Which normalization form means that any multivalued attributes (also called repeating groups) have been removed, so there is a single value (possibly null) at the intersection of each row and column of the table?
First Normal Form
Which normalization form means that any partial functional dependencies have been removed (i.e., nonkey attributes are identified by the whole primary key)?
Second normal form
Whic normalization form means that any transitive dependencies have been removed (i.e., nonkey attributes are identified by only the primary key)
Third normal form
What is a constraint between two attributes in which the value of one attribute is determined by the value of another attribute?
Functional dependency
Example: SSN -> Name, Address, Birthday
A person’s name address and birth date are functionally dependent on tha tperson’s SSN (in other words, there can be only one name, one address, and one birthdate for each SSN)
What is the attribute on the left side of the arrow in a functional dependency?
Determinant
What is an attribute, or combination of attributes, that uniquely indentifies a row in a relation?
Candidate key
What is a relation that has a primary key and in which there are no repeating groups?
First normal form(1NF)
What is a relation in first normal form in which every nonkey attribute is fully functional dependent on the primary key?
Second normal form(2NF)
What is a functional dependency in which one or mor nonkey attributes are functionally dependent on part (but not all) of the primary key?
Partial functional dependency
What is a relation that is in second normal form and has no transitive dependencies?
Third Normal Form (3NF)
What is a functional dependency between the primary key and one or more nonkey attributes that are dependent on the primary key via another nonkey attribute?
Transitive dependency
What is the smallest unit of application data recognized by system software?
Field
What is a detailed coding scheme recognized by system software, such as a DBMS, for representing organizational data?
Data type
(VARCHAR, CHAR, NUMBER etc.)
What is the process of transforming normalized relations into non-normalized physical record specifications?
Denormalization
What is the distribution of rows of a logical relation into several seperate tables?
Horizontal partitioning
What are the advantages of partitioning?
- Efficiency
- Local optimization
- Security
- Recovery and uptime
- Load balancing
What are the disadvantages of partitioning?
- Inconsistent access speed
- Complexity
- Extra space and update time
What is the distribution of the columns of a logical relation into several separate physical tables?
Verical partitioning
What is a named portion of secondary memory (such as a hard disk) allocated for the purpose of storing physical records?
Physical file
What is a named logical storage unit in which data from one or more database tables, views, or other database object may be stored?
Tablespace
What is a contiguous section of disk storage space?
Extent
