Chapter 2: Data Modeling Flashcards
the first step in designing a database, refers to the process of creating a specific data model for a determined problem domain
data modeling
a relatively simple representation, usually graphical, of more complex real-world data structures
data model
a person, place thing, or event about which data will collected and stored
entity
a characteristic of an entity
attribute
describes an association among entities
relationship
a restriction placed on the data
constraint
a brief, precise, and unambiguous description of a policy, procedure , or principle within a specific organization
business rule
this hierarchical structure contains levels, or segments
hierarchical model
the equivalent of a file system’s record type
segment
created to represent complex data relationships more effectively than the hierarchical model
network model
the conceptual organization of the entire database as viewed by the database administrator
schema
defines the portion of the database “seen” by the application programs that actually produce the desired information from the data within the database
subschema
defines the environment in which data can be managed and is used to work with the data in the database
data manipulation language(DML)
enables the database administrator to define the schema components
data definition language (DDL)
describes a precise set of data manipulation constructs based on advanced mathematical concepts
relation
a row in a relation
tuple
performs the same basic functions provided by the hierarchical and network DBMS systems, in addition to a host of other functions that make the relational data model easier to understand and implement
relational database management system (RDBMS)
a graphical tool in which entities and their relationships are pictured
entity relationship(ER) model
uses graphical representation to model database components
entity relationship diagram (ERD)
each row in the relational table
entity instance/ entity occurence
a collection of entities
entity set
used to label the relationship types
connectivity
both data and its relationships are contained in a single structure known as an object
object oriented data model
the ability of an object within class hierarchy to inherit the attributes and methods of the classes above it
inheritance
a language based on object oriented concepts that describes a set of diagrams and symbols you can use to graphically model a system
unified modeling language (UML)
used to represent data and its relationships within the larger UML object oriented system’s modeling language
class diagram
a movement to find new and better ways to manage large amounts of webs and sensor-generated data and derive business insight from it, while simultaneously providing high performance and scalability at a reasonable cost
Big Data
the amount of data being stored
Volume
not only to the speed with which data grows but also to the need to process this data quickly in order to generate information and insight
Velocity
refers to the fact that the data being collected comes in multiple different data formats
Variety
a Java based, open source, high speed, fault-tolerant distributed storage and computational framework
Hadoop
a highly distributed, fault-tolerant file storage system designed to manage large amounts of data at high speeds
Hadoop Distributed File System (HDFS)
a data model based on a structure composed of two data elements: a key and a value or set of values.
key-value
