*An ___internal schema_____ depicts a specific representation of an internal
.model, using the database constructs supported by the chosen database
*When you can change the internal model without affecting the conceptual
model you have ____logical independence__
*The ____Physical model____ operates at the lowest level of abstraction,
describing the way data are saved on the storage media such as magnetic,
solid state, or optical media.
*when you can change the physical model without affectin g the internal
model, you have ___Physical independence____
*The ____internal model____ is the representation of the database as "seen"
by the DBMS
*__Hardware independence_____ means that the model does not depend on
the hardware used in the implementation of the model.
*Also known as a __Conceptual Schema_____, it is the basis for the
identification and high-level description of the main data objects (avoding any
database model-specific details.)
*___software independence_____ means that model does not depend on the
DBMS software used to implement the model.
*The ____Conceptual model___ represents a global view of the entire
database by the entire organization.
*A specific representation of an external view is known as an ___ external
Schema__
*The ____external model____ is the end users' view of the data environment.
*In the early 1970s, the __American National Standards Institute
*(ANSI)________ standards planning and requirements commitee (SPARC)
defined a framework for data modeling based on degrees of data abstraction.
*Some NoSQL databases provide a feature called _eventual
*consistency_____, which means that updates to the database will propagate
through the system and eventually through the system and eventually all data
copies will be consistent
*In particular, they are suited for __Sparse data______ - that is, for cases in
which the number of attributes is very large but the number of actual data
instances is low.
*___NoSQL___ is a large-scale distributed database system that stores
structured and unstructured data inefficient ways.
*__MapReduce___ is an open source application programming interface
(API) that provides fast data analytics services.
*___Hadoop Distributed File System (HDFS)____ is a highly distributed, faulttolerant file storage system designed to manage large amounts of data at high
speeds
*__Hadoop__ is a Java based, open sources, high speed, fault - tolerant
distributed storage and computional framework.
*However, it seems to be Douglas Laney, a data analyst from the Gartner
Group who first described the basic characteristic of Big Data databases:
Volume, Velocity, and Variety or the __3Vs___.
*___Big data_____ refers to a 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.
*Within this environment ___Extensible Markup Language (XML)____
emerged as the de facto standard for the efficient and effective exchange of
structured, semistructured, and unstructured data.
*Facing the demand to support more complex data representations, the
relational model's main vendors evolved the model further and created the
__extended relational data model (ERDM)____
*UML __class diagrams____ are used to represent data and their
relationships within the larger UML object - oriented system's modeling
language.
*Object-oriented data models are typically depicted using __Unified Modeling
Language (UML)_____ class diagrams
*___Inheritance____ is the ability of an object within the class hierarchy to
inherit the attributes and methods of the classes above it
*The ___class hierarchy____ resembles on upside - down tree in which each
class has only one parent.
*A class's __method_____ represents a real-world action such as finding a
selected PERSON'S name, changing a PERSON'S name, or printing a
PERSON'S address.
*A ____class__ is a collection of similar objects with shared structure
(attributes) and behavior (methods)
*The OODM is said to be a _Semantic data model______ because semantic
indicates meaning
*In turn, the OODM is the basis for the ___object - oriented database
management system (OODBMS)_____.
*In the ___Object-Oriented data model (OODM)___, both data and their
relationships are contained in a single structure known as an object.
*The ER model uses the term ___connectivity_____ to label the relationship
types
*Each row in the relational table is known as an _____entity instance__ or
__entity occurrence_____ in the ER model.
*Thus, the ___Entity Relationship Diagram (ERD)___ or ERM, has become a
widely accepted standard for data modeling
*A __relational diagram___ is a representation of the relational database's
entities, the attributes within those entities, and the relationships between
those entities.
*Each row in a relation is called a __tuple___.
*To avoid the complexity of abstract mathematical theory, you can think of a
___relation___ (sometimes called a table) as a matrix composed of
intersecting rows.
*A schema __data definition language (DDL)___ enables the database
administrator to define the schema components
*A __Data Manipulation Language (DML)______ defines the environment in
which data can be managed and is used to work with the data in the
database.
*The ___Subschema____ defines the portion of the database "seen" by the
application programs that actually produced the desired programs that
actually produced the desired information from the data within the database .
*The __schema_____ is the conceptual organization of the entire database as
viewed by the database administrator
*The __network model_____ was created to represent complex data
relationships more effectively than the hierarchical model, to improve
database performance, a database standard
*The __hierarchical model____ was developed in the 1960s to manage large
amounts of data for complex manufacturing projects, such as the Apollo
rocket that landed on the moon in 1969
*___Business Rule___ is a brief, precise, and unambiguous description of a
policy, procedure, or principle within a specific organization
*__Constraint____ is a restriction placed on the data.
*___one-to-one (1:1 or 1..1) relationship___ A retail company's management
structure may require that each of its stores be managed by a single
employee.
*_one-to-many (1:M or 1..*) relationship___ A painter creates many different
painting, but each is painted by only one painter.
*___attribute___ is a characteristic of an entity
*_data model____ is a relatively simple representation, usually graphical of
more complex real - world data structures
* Data modeling The first step in designing a database, refers to the process
of creating a specific data model for a determined problem domain