3. Database
Concept
A database is an organized collection of data,
generally stored and accessed electronically
from a computer system.
The database management system (DBMS) is
the software that interacts with end users,
applications, and the database itself to
capture and analyze the data.
3
4. Data ?
▸ Data is distinct pieces of information,
usually formatted in a special way. ...
Since the mid-1900s, people have used
the word data to mean computer
information that is transmitted or
stored. Strictly speaking, data is the
plural of datum, a single piece of
information.
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Types of Data
6. “
▸Physical view refers to the
way data are physically stored and processed in a
database.
▸Logical view is designed to suit the need of different
users by representing data in a meaningful format.
Another word, the logical view tells the users, in their
term, what is in the database.
6
7. Concept
Check
7
• Describe some of the different
types of data.
• What is the physical view of data
?
• What is the logical view of data ?
8. Logical Data
Organization
? Data organization, in broad terms, refers to the method of
classifying and organizing data sets to make them more
useful. Some IT experts apply this primarily to physical
records, although some types of data organization can
also be applied to digital records.
9. In a logical view Data is
Organized into groups
9
▸ Character – It is most basic logical data element. It is a
single letter; number, or special character, such as
punctuation marks, or a symbol such as $.
▸ Field – The next higher level is a field of related characters Ex – Masurkar (last name) is
in the data field. It represents an attribute.
▸ Record – It is a collection of related fields. Ex – The payroll record of employees.
▸ Table – It is a collection of related record. Ex – Payroll Table.
▸ Database – It is an integrated collection of logically related tables. Ex – The
Personnel Database.
10. Key Field
? Each record in a table has at least one distinctive field,
called as Key Field / Primary Key. Ex – In the Personnel
Database both the payrolls and the benefit tables include
the field Employee ID.
11. Batch processing is where the processing happens of blocks of data that have already been stored
over a period of time. For example, processing all the transaction that have been performed by a
major financial firm in a week. ... Hadoop MapReduce is the best framework for processing
data in batches.
Data processed in a two ways
Real-time data processing is the execution of data in a short time period, providing near-instantaneous
output. The processing is done as the data is inputted, so it needs a continuous stream of input data in order
to provide a continuous output.
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13. Concept
Check
13
• From the logical view, describe how
data is organized or categorized ?
• What are key fields and how are they
used ?
• Compare batch processing and real-
time processing.
14. Database
Redundancy
?
Data redundancy is a condition created within a database or data storage technology in
which the same piece of data is held in two separate places. This can mean two different
fields within a single database, or two different spots in multiple software environments or
platforms.
15. Data Integrity
?
Data integrity is the maintenance of,
and the assurance of the accuracy
and consistency of data over its
entire life-cycle, and is a critical
aspect to the design, implementation
and usage of any system which
stores, processes, or retrieves data.
16. Advantages of Database
16
• Data entry, Update, read and delete
cost is reduced.
• Reduced data redundancy.
• Data sharing is made easy.
• Data inconsistency is reduced.
• The end-user's productivity is
improved.
• Decision making with data is
improved.
• Improved data access.
• Better data integration
Sharing Security
Less data
redundancy
Data integrity
Advantages
of Database
17. Subsystems of Database
?
A database engine is the underlying software component that a database management system
uses to create, read, update and delete data from a database.
Data definition or data description language is a syntax similar to a computer programming
language for defining data structures, especially database schemas.
Data manipulation is the process of changing data to make it easier to read or be more organized.
For example, a log of data could be organized in alphabetical order, making individual entries easier
to locate.
18. Subsystems of Database
?
–
It is used to create application overlay of the DBMS and Database for the use of less sophisticated
users. Data Administration subsystem - used to maintain the over all integrity and security of the
database.
Data administration or data resource management is an organizational function working in the
areas of information systems and computer science that plans, organizes, describes and controls
data resources.
19. Must Know
?
A data dictionary, or metadata repository, as defined in the IBM Dictionary of Computing,
is a“ centralized repository of information about data such as meaning, relationships to
other data, origin, usage, and format". Oracle defines it as a collection of tables with
metadata.
Data maintenance is the process of organizing and curating data according to University
needs. Properly maintaining and caring for data is essential to ensuring that data remains
accessible and usable for its intended purposes.
Additional duties of database administrators include determining processing rights or
determining which people have access to what kinds of data in the database.
20. Must Know
?
Data Warehousing may be defined as a collection of corporate information
and data derived from operational systems and external data sources. A data
warehouse is designed with the purpose of inducing business decisions by
allowing data consolidation, analysis, and reporting at different aggregate levels
Data mining is the process of sorting through large data sets to identify patterns and
establish relationships to solve problems through data analysis. Data mining tools allow
enterprises to predict future trends.
A firewall is a network security device that monitors incoming and outgoing network
traffic and permits or blocks data packets based on a set of security rules. ...
These firewalls examine packets to determine the state of the communication
21. Concept
Check
21
• What is data redundancy ? What is data
integrity ?
• What are the advantages of database ?
• List the five basic subsystems and describe
each.
• What is data dictionary ? Data maintenance
? What are processing rights ?
22. Types of Database
?
Personal databases are typically small database management systems designed to be used by only
one person to organize information. It is also called as individual database. They are stored either
on user’s hard disk or on a LAN file server. It is direct under control of the user.
The company database means information about a company and its employees. The information
could include details about both firmographics and demographic profile of the company. Ex – Data
of a departmental store.
23. Types of Database
?
Commercial databases are simply collections of information presented
electronically. Databases range in size from simple books made searchable, to several billion
records in the larger news databases. The retail database industry is obscure. Costs are highly
variable and difficult to determine in advance. Ex - Oracle. IBM DB2. Microsoft SQL Server.
A distributed DBMS manages the distributed database in a manner so that it appears as one
single database to users. ... A distributed database is a collection of multiple
interconnected databases, which are spread physically across various locations that communicate
via a computer network. Ex – Regional Offices, Company Headquarters.
24. Concept
Check
24
• List four types if databases and
describe each ?
• Give a brief example of each type of
database ?
• What is the difference between a
company database and a distributed
database ?
25. Uses of Database
?
• They store data and provide facilities of searching specific record in given data.
• They store special information used to manage the data. This information is called metadata and it
is not shown to all the people looking at the data.
• They can solve cases where many users want to access (and possibly change) the same entries of
data.
• They manage access rights (who is allowed to see the data, who can change it)
• When there are many users asking questions to the database, the questions must be answered
faster. So, the last person to ask a question, can get an answer in reasonable time.
• Certain attributes are more important than others, they can be used to find other data. This is
called indexing. An index contains all the important data and can be used to find the other data.
• They ensure that the data always has context. There are a lot of different rules that can be added to
tell the database system if the data makes sense. One of the rules might say November has 30 days.
This means if someone wants to enter November 31 as a date, this change will be rejected.
26. Issues of Database
?
• Scalability is a common issue.
• The number one issue is around scale, performance, and cost efficiency.
• A large proportion of our customer base used to struggle to meet their SLAs because their
platforms couldn’t deliver high transactional throughput and low latency, at scale. For them, this
resulted in business losses, reputations being compromised, and general dissatisfaction all around.
• Lack of proper data management, data leakage, unmanaged or uncategorized organizational data,
and lack of constant monitoring are some of the most common reasons
for database vulnerabilities.
• Database vendors need to identify these issues and roll out regular updates or patches to fix them.
27. Database
Security
?
Database security concerns the use of a
broad range of information security
controls to protect databases against
compromises of their confidentiality,
integrity and availability. It involves various
types or categories of controls, such as
technical, procedural/administrative and
physical.
28. Concept
Check
28
• What is a data warehouse ? What
is data mining ?
• What are some database security
concerns ?
• What is a firewall ?
