Unit 10 Databases

Unit 10 Databases
8/26/2016
10 Unit Contents
Unit 10
Section A: Database Basics
Section B: Database Tools
Section C: Database Design
Section D: SQL
Section E: Big Data
Databases
Computer Concepts 2016
ENHANCED EDITION
Unit 10: Databases
10 Section A: Database Basics
10
10
Operational and Analytical Databases
An operational database is used to collect,
modify, and maintain data on a daily basis
An analytical database is used to collect
data that will be used for spotting trends that
offer insights for tactical and strategic
business decisions
Operational and Analytical
Databases
Database Models
Unit 10: Databases
2
3
Unit 10: Databases
10
Operational and Analytical Databases
4
Operational and Analytical Databases
Operational databases perform the following:
Collect and store data
View data
Find data
Update data
Organize data
Distribute data
Move or remove data
Unit 10: Databases
5
Unit 10: Databases
6
1
8/26/2016
10
10
Operational and Analytical Databases
Operational and Analytical Databases
Analytical databases store data that is used
by corporate executives, strategic planners,
and other workers to examine business
metrics
Decision makers can access analytical
databases using an executive dashboard,
provided by software such as iDashboards,
which uses tools for visually displaying query
results
7
Unit 10: Databases
10
10 Database Models
Operational and Analytical Databases
Analytical databases perform the following:
Find relationships and patterns using data
mining
Make predictions using predictive analytics
Examine multiple factors using OLAP
(online analytical processing)
Unit 10: Databases
The underlying structure of a database is
referred to as a database model
One of the simplest models for storing data is
a flat file that consists of a single, twodimensional table of data elements
A structured file uses a uniform format to
store data for each person or thing in the file
9
10 Database Models
Unit 10: Databases
10
10 Database Models
 A field contains the smallest unit of meaningful
information; it is the basic building block for a
structured file or database
 A variable-length field is like an accordion—it
expands to fit the data you enter
 A fixed-length field contains a predetermined
number of characters (bytes)
 In the world of databases, a record refers to a
collection of data fields; the template for a record is
a record type
Unit 10: Databases
8
Unit 10: Databases
 In database jargon, a relationship is an association
between data that’s sorted in different record types
 An important aspect of the relationship between
record types is cardinality, which refers to the
number of associations that can exist between two
record types
 The relationship between record types can be
depicted graphically with an entity-relationship
diagram (sometimes called an ER diagram or ERD)
11
Unit 10: Databases
12
2
8/26/2016
10 Database Models
10 Database Models
Many database models keep track of
relationships among data, but there are
different techniques for doing so
A hierarchical database allows one-to-one
and one-to-many relationships which are
linked in a hierarchical structure
Unit 10: Databases
13
10 Database Models
14
10 Database Models
 A relational database stores data in a collection of
related tables
 Each table is a sequence of records, similar to a flat
file
 A multidimensional database organizes
relationships over three or more dimensions; in the
context of databases, a dimension is a layer based
on a data element, such as a product, place, or
customer, that can be used to categorize data
 A graph
database offers
an alternative
way to track
relationships; its
structure
resembles
sociograms with
their interlinked
nodes
Unit 10: Databases
Unit 10: Databases
15
10 Database Models
Unit 10: Databases
16
10 Database Models
 An object database, also called an object-oriented
database, stores data as objects, which can be grouped
into classes and defined by attributes and methods
 Object databases excel at representing objects that
have slightly different attributes, which is the case in
many real-world business applications
 A document-oriented database stores unstructured
data, such as the text of a speech
 XML (eXtensible Markup Language) is a popular tool
used to format document databases
Unit 10: Databases
17
Unit 10: Databases
18
3
8/26/2016
10 Section B: Database Tools
10 Database Tool Basics
Database Tool Basics
Dedicated Applications
Word Processor Data Tools
Spreadsheet Data Tools
Database Management Systems
Unit 10: Databases
19
10 Database Tool Basics
Data dependence is a term that refers to
data and program modules being so tightly
interrelated that they become difficult to
modify
Modern database tools support data
independence, which entails separating data
from the programs that manipulate it
Unit 10: Databases
20
10 Dedicated Applications
 The simplest tools for managing data are dedicated
applications for specific data management tasks,
such as keeping track of appointments or
maintaining an address book
 To use one of these tools, simply enter your data;
the software includes menus that allow you to
manipulate your data once it is entered
 Dedicated applications are easy to use, however
they generally don’t allow users to add fields or
change field names
Unit 10: Databases
21
10 Dedicated Applications
Unit 10: Databases
22
10 Word Processor Data Tools
 Word processing software may include tools for working
with unstructured or structured data; these tools can
sort a list or create a file of data for mail merges
 Most word processing software includes a sort feature
that can be used to arrange a simple list in alphabetical
or numeric order
 A single-level sort uses only one field to arrange
records
 A multi-level sort arranges information by more than
one field
Unit 10: Databases
23
Unit 10: Databases
24
4
8/26/2016
10 Word Processor Data Tools
10 Spreadsheet Data Tools
Spreadsheets are organized in table format,
so it makes sense that they can be used for
sorting data
Depending on the spreadsheet software, it
may be possible to sort records, validate
data, search for records, perform simple
statistical functions, and generate graphs
Unit 10: Databases
25
10 Spreadsheet Data Tools
Unit 10: Databases
26
10 Database Management Systems
 When a word processor or spreadsheet isn’t
sufficient to handle a data set, a DBMS is an option
that offers a set of development tools for creating
and accessing databases
 The term DBMS (database management system)
refers to software that manages data stored in a
database
 Filemaker Pro and Microsoft Access are easy-touse DBMSs that are a good fit for small businesses
and individuals
Unit 10: Databases
27
10 Database Management Systems
28
10 Database Management Systems
 Modern DBMSs work with many kinds of data
including text, numbers, images, PDFs, and audio
files
 Today, databases might reside on a in-house
server, or on a cloud based server, or on distributed
servers scattered throughout the world
 DBMSs handle the details of how to most efficiently
arrange data on a storage medium for optimal
access speed
Unit 10: Databases
Unit 10: Databases
29
 DBMSs require
security features
to ensure data
confidentiality,
protect against
insider threats,
and block
unauthorized
access
Unit 10: Databases
30
5
8/26/2016
10 Section C: Database Design
10 Defining Fields
There are three core elements in a relational
database: fields, tables, and relationships
The term database structure refers to the
arrangement of fields, tables, and
relationships in a database
The first step in structuring a relational
database is to determine what data should be
collected and stored
Defining Fields
Data Types
Normalization
Sorting and Indexing
Designing the Interface
Designing Report Templates
Unit 10: Databases
31
10 Defining Fields
10 Data Types
 A computed field is a calculation that a DBMS
performs, similar to the way a spreadsheet
computes a formula
 A field format is a template that adds the correct
formatting as data is entered
 A field validation rule is a specification that the
database designer sets up to filter data entered into
a particular field
 A lookup routine validates a field entry by
checking data in an in-house or third-party database
Unit 10: Databases
33
10 Data Types
 The data that can be entered into a field depends
on the field’s data type
 A data type specifies the way data is represented
on physical storage media and RAM
 Data types:
 Real – used for fields that contain numbers with decimal
places
 Integer – used for fields that contain whole numbers
 Date – stores dates in a format that allows them to be
manipulated
Cont…
Unit 10: Databases
34
10 Normalization
 Text – assigned to fixed-length fields that hold
character data
 Memo – provides a variable-length field for user
comments
 Logical (Boolean) – used for true/false and
yes/no data
 BLOB (binary language object) – can be any
type of data
 Hyperlink – stores URLs used to link from a
database to a Web page
Unit 10: Databases
32
Unit 10: Databases
A process called normalization helps
database designers create a database
structure that minimizes storage space and
increases processing efficiency
The goal of normalization is to minimize data
redundancy—the amount of data that is
duplicated in a database
35
Unit 10: Databases
36
6
8/26/2016
10 Sorting and Indexing
10 Designing the Interface
 A table’s physical sort order is the order in which
data are arranged on storage devices
 A sort key is the column of data that is used as the
basis for rearranging the data
 Sorted tables produce faster queries and updates
using clever algorithms to find data
 A database index contains a list of keys, and each
key provides a pointer to the data that contains the
rest of the fields related to that key
The following guidelines list strategies for
producing well designed database interfaces:
Cont…
Unit 10: Databases
37
10 Designing the Interface
Unit 10: Databases
38
10 Designing the Interface
39
10 Designing Report Templates
Unit 10: Databases
40
10 Section D: SQL
A report is a printed or screen-based list of
some or all of the data in a database
Most DBMSs include a report generator,
which is a software tool for specifying the
content and format for a database report
A report template contains the outline or
general specifications for a report
Unit 10: Databases
Unit 10: Databases
SQL Basics
Adding Records
Searching for Information
Updating Fields
Joining Tables
41
Unit 10: Databases
42
7
8/26/2016
10 SQL Basics
10 SQL Basics
 Commands processed by the DBMS are issued
using computer programming languages designed
for databases
 These languages are sometimes called query
languages because one of their main capabilities is
to request data from a database
 The database client software collects input from the
user and then converts it into an SQL query, which
can operate directly on the database to carry out
the user’s instructions
Unit 10: Databases
43
10 SQL Basics
 The SQL query language provides a collection of
special command words called SQL keywords,
such as SELECT, FROM, INSERT, and WHERE
 Most SQL queries can be divided into three simple
elements that specify an action, the name of a
database table, and a set of parameters
 An SQL query begins with an action keyword, or
command, which specifies the operation you want
carried out
 Parameters are detailed specifications for a
command
Unit 10: Databases
44
10 Adding Records
A database record contains information about
an entity, such as a customer, an online
purchase, an ATM withdrawal, or a social
media post
The data is bundled into an SQL statement
that is handled by the DBMS
Using the INSERT command, a user can add
data to a record
Unit 10: Databases
45
10 Searching for Information
46
10 Updating Fields
One of the most common database
operations is to query for particular record or
a group of records by using the SELECT
command
The database client software uses a search
specification to create the SQL query; a result
is generated for this query
SQL uses Boolean operators such as AND,
OR, and NOT to form complex queries
Unit 10: Databases
Unit 10: Databases
47
Updates and modifications to the contents of
a database field are made by using the SQL
UPDATE command
The UPDATE function works only for records
that have similar characteristics
Custom programming is required to perform
global operations on information that does
not have any similar characteristics
Unit 10: Databases
48
8
8/26/2016
10 Joining Tables
10 Section E: Big Data
Big Data Basics
Big Data Analytics
NoSQL
 In SQL terminology, creating a relationship
between tables is referred to as joining
tables
 The SQL JOIN command allows users to
temporarily join and simultaneously access
the data in more than one table
 When joining two tables, the convention is to
use dot notation for field names; SQL uses
dot notation to make distinctions between data
Unit 10: Databases
49
10 Big Data Basics
50
10 Big Data Basics
Big data refers to the huge collections of
data that are difficult to process, analyze, and
manage using conventional database tools
An example of big data is the 1 million
transactions generated by Walmart sales
registers every hour
Big data is a relatively new phenomenon that
businesses are just beginning to deal with
Unit 10: Databases
Unit 10: Databases
51
10 Big Data Analytics
Big data is characterized as having:
High Volume
High Velocity
Diversified Variety
Unknown Veracity
Low-density Value (low-density data refers
to large volumes of data containing
unimportant details)
Unit 10: Databases
52
10 Big Data Analytics
Mainstream big data exploration produces
commercial benefits
A high percentage of today’s expenditures on
big data are for technologies that enhance
the customer experience and provide
targeted marketing solutions
Real-time analysis and decision making are
popular reasons to invest in big data
technologies
Unit 10: Databases
53
Unit 10: Databases
54
9
8/26/2016
10 NoSQL
10 NoSQL
The term NoSQL is used to refer to a group
of technologies for managing databases that
do not adhere to the relational model and
standard SQL query language
NoSQL technologies are effective for building
and managing non-relational databases
containing big data that may be unstructured
and may be distributed across multiple
servers
Unit 10: Databases
55
10 NoSQL
56
10 NoSQL
 Unstructured and semi-structured data—such as
tweets, email messages, blog posts, and videos—
are difficult to mold into fixed structures
 Relational databases are organized according to a
schema, which is a blueprint for its structure; rows,
columns, and tables of a database are part of its
schema
 NoSQL tools create schema-less databases,
allowing data structures such as fields to be added
Unit 10: Databases
Unit 10: Databases
The simplest structure for storing data in a
NoSQL database is the key-value data
model; each data item has a key that is a
unique identifier similar to a relational
database key such as CustomerID
The column-oriented data model stores
data in columns, rather than in rows, so it
works well in situations where the focus is on
analysis of chunks of data
57
Unit 10: Databases
58
10 NoSQL
Popular NoSQL tools include:
Unit 10 Complete
MongoDB
Cassandra
Hbase
Neo4j
SimpleDB
Hive
Google Big Table
Voldemort
Unit 10: Databases
Computer Concepts 2016
59
10
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF

advertisement