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DATA MANAGEMENT FOUNDATIONS STUDY
GUIDE C175 QUESTIONS WITH CORRECT
ANSWERS GRADED A+ GUARANTEED PASS!
"Entity - CORRECT ANSWER=> o A person, place, thing, or event
o Represents a particular type of object and is distinguishable o Each occurrence is unique and distinct EXAMPLE: John Smith, John Strickland. Each customer is unique and distinct"
"· Attribute - CORRECT ANSWER=> o A characteristic of an Entity
o Equivalent to fields in a file system EXAMPLE: Customers last name, First name, Phone number or Address"
"· Relationship - CORRECT ANSWER=> o Describes an association among entities
o Are bidirectional"
"· Constraint - CORRECT ANSWER=> o Restriction placed on data
o Helps ensure data integrity o Expressed in the form of rules EXAMPLE: 6,000 and 350,000, GPA must be between 0.00 and 4.00 or Class must have one and only one teacher"
"· Business Rules - CORRECT ANSWER=> A brief, precise, in unambiguous description, policy,
procedure, or principle within a organization"
"Business Rules for Objects - CORRECT ANSWER=> · Noun in a business will translate into an entity in
the model · Verb (active or passive) that associates the nouns will translate into a relationship among the entities"
"· Relational Model (RM) - CORRECT ANSWER=> "
"o Relation - CORRECT ANSWER=> Table
· Two-dimensional structure composed of intersecting rows and columns o Provides a minimum level of control redundancy to eliminate most of the word unseen commonly found in file systems"
"Tuple - CORRECT ANSWER=> row"
"attribute - CORRECT ANSWER=> column"
"· Relational Database Management System (RDBMS) - CORRECT ANSWER=> o Performs same
functions provided by Hierarchical and Network DBMS o Advantage is its ability to hide complexities of relational model from the user o Manages all physical details, while user sees relational database as a collection of tables"
"· Entity Relationship Model (ER) - CORRECT ANSWER=> o Represented in an Entity Relationship
Diagram (ERD) which uses graphical representations to model database components"
"One to One (1:1 or 1..1) - CORRECT ANSWER=> o A single record in the first table is related to only
one record in the second table And o A single record in the second table is related to only one record in the first table"
"· One to Many (1:M or 1..*) - CORRECT ANSWER=> o A single record in the first table can be related to
one or more records in the second table But o a single record in the second table can be related to only one record in the first table Example: Each painting was created by one and only one painter Each painter could have created many paintings"
"· Many to Many (M:N or ..) - CORRECT ANSWER=> o A single record in the first table can be related
to one or more records in the second table And o A single record in the second table can be related to one or more records in the first table Ex. An employee may learn many job skills, and each skill can be learned by many employees."
"knowledge - CORRECT ANSWER=> o Information and facts about a specific subject
o Implies familiarity awareness and understanding of Information o Key Characteristic is that New Knowledge can be derived from Old Knowledge"
"data management - CORRECT ANSWER=> o A discipline that focuses on the proper generation,
storage, and retrieval of data"
"role of the DBMS - CORRECT ANSWER=> o An intermediary between user and database
o Receives all application requests and translates them into complex operations"
"advantages of DBMS - CORRECT ANSWER=> -Improves data sharing
-improves data security
· Supports the storage and management of Semi Structured XML data"
"NoSQL database - CORRECT ANSWER=> o New generation of DBMS not based on traditional relational
database model o Designed to handle unprecedented volumes, variety types, structure of data IOT support the velocity of data operations required in businesses"
"Why Database Design is Important - CORRECT ANSWER=> · A well-designed database facilitates data
management and generates accurate invaluable information"
"problems with file system data processing - CORRECT ANSWER=> Lengthy development times,
Difficulty of getting quick answers, Complex system administration, Lack of security and limited data sharing, Extensive programming"
"Structural dependence - CORRECT ANSWER=> o Data characteristic in which a change in the database
schema, affects database access, requiring changes to all access programs file changes"
"· Structural Independence - CORRECT ANSWER=> o Data characteristic in which changes in the
database schema DOES NOT affect database access"
"· Data Dependence - CORRECT ANSWER=> o A data collection in which data representation and
manipulation are dependent on physical data storage characteristics affecting access to the data"
"· Data Independence - CORRECT ANSWER=> o A data collection in which data representation and
manipulation IS NOT dependent on physical data storage characteristics and DOES NOT affect access the data"
"· Data Redundancy - CORRECT ANSWER=> o Same data stored unnecessarily in multiple places
(scattered in different locations "Islands of Information")"
"o Data Integrity is: - CORRECT ANSWER=> · Data that is accurate - no data inconsistencies
· Data that is verifiable - will always yield consistent results"
"· Data Anomalies - CORRECT ANSWER=> o Forces field value changes in many different locations
o Develops when not all required changes in the redundant data or made successfully o Types of data anomalies include Update, Insertion or Deletion"
"o Data Dictionary Management - CORRECT ANSWER=> · DBMS provides data abstraction, and it
removes structural and data dependence from the system"
"o Data Storage Management - CORRECT ANSWER=> · Data storage management is important for
database Performance Tuning o Performance tuning allows for the database to access data fast and efficiently"
"Data Modeling - CORRECT ANSWER=> the first step in designing a database, is the process of creating
a specific model for a determined problem domain"
"Problem Domain - CORRECT ANSWER=> a clearly defined area within the real-world environment,
with a well-defined scope and boundaries that will be systematically addressed"
"Data Model - CORRECT ANSWER=> o Main Function: Help understand the complexities of the
environment Represents data structures, characteristics, relations, constraint, transformations, in other constructs with the purpose of supporting a specific problem domain o Implementation ready data models should contain: · Description of the data structure that will store end user data · A set of enforceable rules to guarantee integrity · A data manipulation methodology to support data transformations"
"The Importance of Data Models - CORRECT ANSWER=> · Data models are communications tools
· Facilitate interaction among the designer, the applications programmer, and the end user"
"big data characteristics - CORRECT ANSWER=> o Volume- The amounts of data being stored
o Velocity- The speed with which data grows. The need to process data quickly to generate information and insight o Variety- The data being collected comes in multiple different data formats"
"big data - CORRECT ANSWER=> · Movement to find new and better ways to manage large amounts of
web/ sensor-generated data and derive business insight from it, while simultaneously providing high performance and scalability at a reasonable cost"
"Intersection data - CORRECT ANSWER=> · Describes the relationship between two entities"
"o Associative Entity - CORRECT ANSWER=> · Indicates a relationship between one entity and another
· Specifically, that an entity has been involved in an action that involves another · Includes any intersection data that describes the relationship in its information"
"Logical View of Data - CORRECT ANSWER=> · Relational model enables you to view data logically
rather than physically. o Logical view facilitated by relationships based on logical construct call a relation"
"domain - CORRECT ANSWER=> · In data modeling, the construct used to organize and describe an
attribute's set of possible values."
"index - CORRECT ANSWER=> o An orderly arrangement of keys and pointers used to logically access
rows in a table o Composed of an Index Key and Set of Pointers o Used to retrieve data more efficiently o Used by DBMS to retrieve data ordered by a specific attribute or attributes"
"· Existence Dependence - CORRECT ANSWER=> o when an entity can exist in the database when
associated with another related entity occurrence o Exists if an entity has a mandatory foreign key attribute that cannot be null"
"Existence-Independent - CORRECT ANSWER=> when entities can exist apart from all of its related
entities · Referred to as a Strong or Regular Entity"
"· Recursive Relationship - CORRECT ANSWER=> o Relationship which can exist between occurrences
of the same entity set"
"Normalization - CORRECT ANSWER=> o A process for evaluating and correcting table structures to
minimize data redundancies, thereby reducing the likelihood of data anomalies o Properly designed 3NF structures also meet the requirements of fourth normal form (4NF)"
"First Normal Form (1NF) - CORRECT ANSWER=> · All key attributes are defined
· No repeating groups in the table (each row/column intersection contains one and only one value, not a set of values) · Attributes are dependent on the primary key o All relational tables satisfy the 1NF requirements"
"Second Normal Form (2NF) - CORRECT ANSWER=> · It is in 1NF
AND
· No partial dependencies (no attribute is dependent on only a portion of the primary key)"
"Third Normal Form (3NF) - CORRECT ANSWER=> · It is in 2NF
AND
There are no transitive dependencies"
"<= - CORRECT ANSWER=> less than or equal to"
">= - CORRECT ANSWER=> greater than or equal to"
"<>, != - CORRECT ANSWER=> not equal to"
"Business Intelligence - CORRECT ANSWER=> · Comprehensive, cohesive, and integrated set of tools
and processes used to capture, collect, integrate, store, and analyze data with the purpose of generating and presenting information to support business decision making"
"data analysis: explanatory - CORRECT ANSWER=> · Uses existing data in the data store to discover
relationships and their types"
"data analysis: predictive - CORRECT ANSWER=> · Creates statistical models of the data that allow
predictions of future values and events"
"Extraction - CORRECT ANSWER=> · Raw data is copied or exported from source locations to a staging
area · Can be structured or unstructured · Data is tagged with metadata, source systems is identified, time stamped, and other important metadata · Requires executing programs to: o Purge/Expand existing staging tables or locations o Extract data from source systems o Load Staging Area with data/metadata"
"transformation - CORRECT ANSWER=> · Uses tools scripts and programs to perform tasks such as:
o Merging data o Sorting data o Converting data o Aggregating data o Tagging data o Key data o Deriving columns · Data that does not conform to transformation processing is sent to rework tables"
"hashed files - CORRECT ANSWER=> · Uses hash functions to decide where records should be placed
on a disk · Allows for faster data look up without the use of an index file"
"data - CORRECT ANSWER=> raw facts not processed to reveal meaning. Requires transformation to
better understand."
"information - CORRECT ANSWER=> o Produced by Processing Raw Data to reveal its meaning
o Key to good decision making and business survival is accurate, relevant, and timely information"
