Name : Genesius Hartanto
NIM : 1701308971
Class : 01PCT
Professor : Mr. Tri Djoko Wahjono, Ir., M.Sc.
Class : 01PCT
Professor : 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.