ASSIGNMENT CHAPTER10
Discovering Computers - Student Assignment Chapter 10 Review
(Mr. Tri Djoko Wahjono, Ir., M.Sc.)
Discovering Computers
Student Assignment - Chapter 10 Review
Page 542-543
Name : Nova Jingga
Class : 01PCT
Student ID : 1701313473
Lecture : Mr. Tri Djoko Wahjono, Ir., M.Sc.
1.
What is a Database, and How does a Database
interact with data and information?
A database is an organized
collection of data. The data are typically organized to model relevant aspects
of reality in a way that supports processes requiring this information. For
example, modeling the availability of rooms in hotels in a way that supports
finding a hotel with vacancies.
Database management systems (DBMSs) are
specially designed applications that interact with the user, other
applications, and the database itself to capture and analyze data. A
general-purpose database management system (DBMS) is a software system
designed to allow the definition, creation, querying, update, and
administration of databases. Well-known DBMSs include MySQL, PostgreSQL, SQLite,
Microsoft SQL Server, Oracle, SAP, dBASE, FoxPro, IBM DB2, LibreOffice Base and
FileMaker Pro. A database is not generally portable across different DBMS, but
different DBMSs can interoperate by using standards such as SQL and ODBC or JDBC
to allow a single application to work with more than one database.
Formally, the term "database"
refers to the data itself and supporting data structures. Databases are created
to operate large quantities of information by inputting, storing, retrieving,
and managing that information. Databases are set up so that one set of software
programs provides all users with access to all the data.
A "database management
system" (DBMS) is a suite of computer software providing the interface
between users and a database or databases. Because they are so closely related,
the term "database" when used casually often refers to both a DBMS
and the data it manipulates.
Outside the world of professional information
technology, the term database is sometimes used casually to refer to any
collection of data (perhaps a spreadsheet, maybe even a card index). This
article is concerned only with databases where the size and usage requirements
necessitate use of a database management system.
The interactions catered for by most
existing DBMS fall into four main groups:
·
Data definition. Defining new data
structures for a database, removing data structures from the database,
modifying the structure of existing data.
·
Update. Inserting, modifying, and
deleting data.
·
Retrieval. Obtaining information either
for end-user queries and reports or for processing by applications.
·
Administration. Registering and
monitoring users, enforcing data security, monitoring performance, maintaining data
integrity, dealing with concurrency control, and recovering information if the
system fails.
A DBMS is responsible
for maintaining the integrity and security of stored data, and for recovering
information if the system fails.
Both a database and
its DBMS conform to the principles of a particular database model. "Database
system" refers collectively to the database model, database management
system, and database.
Physically, database
servers are dedicated computers that hold the actual databases and run only the
DBMS and related software. Database servers are usually multiprocessor
computers, with generous memory and RAID disk arrays used for stable storage.
RAID is used for recovery of data if any of the disks fails. Hardware database
accelerators, connected to one or more servers via a high-speed channel, are
also used in large volume transaction processing environments. DBMSs are found
at the heart of most database applications. DBMSs may be built around a custom multitasking
kernel with built-in networking support, but modern DBMSs typically rely on a
standard operating system to provide these functions.
Since DBMSs comprise a significant economical market, computer and storage
vendors often take into account DBMS requirements in their own development
plans.
Databases and DBMSs
can be categorized according to the database model(s) that they support (such
as relational or XML), the type(s) of computer they run on (from a server
cluster to a mobile phone), the query language(s) used to access the database
(such as SQL or XQuery), and their internal engineering, which affects
performance, scalability, resilience, and security.
2.
What is Data Integrity, and what are the
qualities of valuable information?
Data integrity
refers to maintaining and assuring 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. The term data
integrity is broad in scope and may have widely different meanings
depending on the specific context - even under the same general umbrella of computing.
This article provides only a broad overview of some of the different types and
concerns of data integrity.
Data integrity is the opposite of data
corruption, which is a form of data loss. The overall intent of any data
integrity technique is the same: ensure data is recorded exactly as intended
(such as a database correctly rejecting mutually exclusive possibilities,) and
upon later retrieval, ensure the data is the same as it was when it was
originally recorded. In short, data integrity aims to prevent unintentional
changes to information. Data integrity is not to be confused with data security,
the discipline of protecting data from unauthorized parties.
Any unintended changes to data as the
result of a storage, retrieval or processing operation, including malicious
intent, unexpected hardware failure, and human error, is failure of data
integrity. If the changes are the result of unauthorized access, it may also be
a failure of data security. Depending on the data involved this could manifest
itself as benign as a single pixel in an image appearing a different color than
was originally recorded, to the loss of vacation pictures or a
business-critical database, to even catastrophic loss of human life in a Life-critical
system.
3.
What is meant by Character, Field, Record, and
File?
Data is classified in a hierarchy, with
each level of data consisting of one or more items from the lower level. A bit
is the smallest unit of data a computer can process. Eight bits grouped
together in an unit form a byte, and each byte represents a single character, which can be a number,
letter, space, punctuation mark, or other symbol.
A Field
is a combination of one or more related characters or bytes and is the smallest
unit of data a user accesses.
A Record
is a group of related fields.
A Data
File is a collection of related records stored on a storage medium such as
a hard disk or optical disc.
4.
What are file maintenance techniques and
validation techniques?
File maintenance refers to the procedures
that keep data current. File maintenance procedures include adding records to
correct inaccurate data or to update old data with new data, and deleting
records when they no longer are needed.
Validation is the process of comparing data
with a set of rules or values to find out if the data is correct. Many programs
perform a validity check that analyzes data, either as you enter it or
after you enter it, to help ensure that it is correct.
Types of validity checks include an
alphabetic check, a numeric check, a range check, a consistency check, a
completeness check, and a check digit.
5.
How is a file processing approach different from
database approach?
Each department or area within an
organization has its own set of data files. The records in one file may not
relate to the records in any other file. Two major weaknesses of file
processing systems are redundant data (duplicated data) and isolated data. With
a database approach, many programs
and users share the data in database. The database approach reduces data
redundancy, improves data integrity, shares data, permits easier access, and
reduces development time. A database, however, can be more complex than a file
processing system, requiring special training and more computer memory,
storage, and processing power than file processing systems. Data in a database
also can be more vulnerable than data in file processing systems.
6.
What functions are common to most database
management systems?
Database management system - (DBMS)
A suite of programs which typically manage large structured sets of persistent
data, offering ad hoc query facilities to many users. They are widely used in
business applications.
A database management system (DBMS) can be an extremely complex set of software programs that controls the organization, storage and retrieval of data (fields, records and files) in a database. It also controls the security and integrity of the database. The DBMS accepts requests for data from the application program and instructs the operating system to transfer the appropriate data.
When a DBMS is used, information systems can be changed much more easily as the organization's information requirements change. New categories of data can be added to the database without disruption to the existing system.
Data security prevents unauthorized users from viewing or updating the database. Using passwords, users are allowed access to the entire database or subsets of the database, called subschemas (pronounced "sub-skeema"). For example, an employee database can contain all the data about an individual employee, but one group of users may be authorized to view only payroll data, while others are allowed access to only work history and medical data.
The DBMS can maintain the integrity of the database by not allowing more than one user to update the same record at the same time. The DBMS can keep duplicate records out of the database; for example, no two customers with the same customer numbers (key fields) can be entered into the database.
Query languages and report writers allow users to interactively interrogate the database and analyze its data.
If the DBMS provides a way to interactively enter and update the database, as well as interrogate it, this capability allows for managing personal databases. However, it may not leave an audit trail of actions or provide the kinds of controls necessary in a multi-user organization. These controls are only available when a set of application programs are customized for each data entry and updating function.
A business information system is made up of subjects (customers, employees, vendors, etc.) and activities (orders, payments, purchases, etc.). Database design is the process of deciding how to organize this data into record types and how the record types will relate to each other. The DBMS should mirror the organization's data structure and process transactions efficiently.
Organizations may use one kind of DBMS for daily transaction processing and then move the detail onto another computer that uses another DBMS better suited for random inquiries and analysis. Overall systems design decisions are performed by data administrators and systems analysts. Detailed database design is performed by database administrators.
The three most common organizations are the hierarchical database, network database and relational database. A database management system may provide one, two or all three methods. Inverted lists and other methods are also used. The most suitable structure depends on the application and on the transaction rate and the number of inquiries that will be made.
Database machines are specially designed computers that hold the actual databases and run only the DBMS and related software. Connected to one or more mainframes via a high-speed channel, database machines are used in large volume transaction processing environments. Database machines have a large number of DBMS functions built into the hardware and also provide special techniques for accessing the disks containing the databases, such as using multiple processors concurrently for high-speed searches.
The world of information is made up of data, text, pictures and voice. Many DBMSs manage text as well as data, but very few manage both with equal proficiency. Throughout the 1990s, as storage capacities continue to increase, DBMSs will begin to integrate all forms of information. Eventually, it will be common for a database to handle data, text, graphics, voice and video with the same ease as today's systems handle data.
A database management system (DBMS) can be an extremely complex set of software programs that controls the organization, storage and retrieval of data (fields, records and files) in a database. It also controls the security and integrity of the database. The DBMS accepts requests for data from the application program and instructs the operating system to transfer the appropriate data.
When a DBMS is used, information systems can be changed much more easily as the organization's information requirements change. New categories of data can be added to the database without disruption to the existing system.
Data security prevents unauthorized users from viewing or updating the database. Using passwords, users are allowed access to the entire database or subsets of the database, called subschemas (pronounced "sub-skeema"). For example, an employee database can contain all the data about an individual employee, but one group of users may be authorized to view only payroll data, while others are allowed access to only work history and medical data.
The DBMS can maintain the integrity of the database by not allowing more than one user to update the same record at the same time. The DBMS can keep duplicate records out of the database; for example, no two customers with the same customer numbers (key fields) can be entered into the database.
Query languages and report writers allow users to interactively interrogate the database and analyze its data.
If the DBMS provides a way to interactively enter and update the database, as well as interrogate it, this capability allows for managing personal databases. However, it may not leave an audit trail of actions or provide the kinds of controls necessary in a multi-user organization. These controls are only available when a set of application programs are customized for each data entry and updating function.
A business information system is made up of subjects (customers, employees, vendors, etc.) and activities (orders, payments, purchases, etc.). Database design is the process of deciding how to organize this data into record types and how the record types will relate to each other. The DBMS should mirror the organization's data structure and process transactions efficiently.
Organizations may use one kind of DBMS for daily transaction processing and then move the detail onto another computer that uses another DBMS better suited for random inquiries and analysis. Overall systems design decisions are performed by data administrators and systems analysts. Detailed database design is performed by database administrators.
The three most common organizations are the hierarchical database, network database and relational database. A database management system may provide one, two or all three methods. Inverted lists and other methods are also used. The most suitable structure depends on the application and on the transaction rate and the number of inquiries that will be made.
Database machines are specially designed computers that hold the actual databases and run only the DBMS and related software. Connected to one or more mainframes via a high-speed channel, database machines are used in large volume transaction processing environments. Database machines have a large number of DBMS functions built into the hardware and also provide special techniques for accessing the disks containing the databases, such as using multiple processors concurrently for high-speed searches.
The world of information is made up of data, text, pictures and voice. Many DBMSs manage text as well as data, but very few manage both with equal proficiency. Throughout the 1990s, as storage capacities continue to increase, DBMSs will begin to integrate all forms of information. Eventually, it will be common for a database to handle data, text, graphics, voice and video with the same ease as today's systems handle data.
7.
What are Characteristics of relational,
object-oriented, and multidimensional databases?
This isn’t the first time in recent
history that new types of database products have emerged and overcome RDBMS
inefficiencies. Back in the 1980s, a class of applications was identified in
which RDBMS products ill-handled the data-management needs (especially the
generation of RDBMSs available at that time).
These applications
all needed user-specified data types that varied among different
implementations. For example, computer-aided design/computer-aided
manufacturing (CAD/CAM) applications had to be capable of specifying data types
that related to product drawings, blueprints, and other related factors.
Computer-aided
software engineering (CASE) needed data types to represent applications and
systems, databases, graphical representations of entities and attributes,
process and data flows, and other parts of the application-development process.
What resulted was object-oriented
database management systems (ODBMSs), which eliminated the table-row-column
structures of relational databases and instead introduced the concepts of
classes and subclasses (or types and subtypes), objects, properties, methods,
and the other parts of object-oriented technology directly into the database
engine.
Because RDBMS
technology wasn’t well-suited to multidimensional analysis, particularly in
terms of performance, vendors set out to develop their own structures tuned and
optimized for improved performance.
If you track
happenings in the database management world, you’re probably familiar with the
convergence of relational and object-oriented database technology. RDBMS
products are being equipped with object-oriented extensions.
Arguably, this
approach to handling complex data types (objects) has won out over
non-relational products (“pure” ODBMSs), primarily because of the large
installed base of relational products and applications running on top of them.
Will the same thing happen in the data warehousing world — relational
technology overtaking and then overwhelming specialized multidimensional
products? Only time will tell.
8.
How are Web Databases Accessed?
You can use Access 2010 and Access
Services, a new component of SharePoint, to build web database applications.
This helps you:
·
Secure and manage access to your data
·
Share data throughout an organization,
or over the Internet
Note A user account is required to use a web database. Anonymous access is not supported.
Note A user account is required to use a web database. Anonymous access is not supported.
·
Create database applications that don't
require Access to use
9.
What are the responsibilities of Database
Analysts and Administrators?
A database administrator's
responsibilities can include the following tasks:
·
Installing and upgrading the database
server and application tools
·
Allocating system storage and planning
future storage requirements for the database system
·
Modifying the database structure, as
necessary, from information given by application developers verbally
·
Enrolling users and maintaining system security
·
Ensuring compliance with database
vendor license agreement
·
Controlling and monitoring user access
to the database
·
Monitoring and optimizing the
performance of the database
·
Planning for backup and recovery of
database information
·
Maintaining archived data
·
Backing up and restoring databases
·
Contacting database vendor for technical
support
·
Generating various reports by querying
from database as per need.
