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K.S.R College Of Engineering , Tiruchengode -637215
Department Of Information Technology
Year/Sem: III/V Subject: Client Server Computing
2 marks Questions and Answers1. Define client and server.
Clients and servers are separate logical entities that work together over a
network to accomplish a task.
Clients send requests to the server. The server in turn sends response to the
client.
2. Define Client – Server Computing Era:
Client/Server reshaped the way of computers being used.
Client/Server become mandatory in all computer oriented fields
Internet is a good example for the Client/Server concept.
3. What are the characteristics of client and server?
Service
Shared resource
Asymmetrical Protocols
Transparency of location.
Mix-and-match.
Message-based exchanges.
Encapsulation of services.
Scalability.
Integrity.
4. Define transparency of location.
The server is a process that can reside on the same machine as the client or on a
different machine across a network. Client/server software usually masks the location of
the server from the clients by redirecting service calls when needed. This is referred as
transparency of location.
5. Define horizontal and vertical scalability.
Horizontal scaling means adding or removing client workstations with only a
slight performance impact.
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Vertical scaling means migrating to a larger and faster server machine or
multiservers.
6. What are the uses of file servers?
The client (typically a PC) passes requests for file records over a network to the
file server. File servers are useful for sharing files across a network. They are
indispensable for creating repositories of documents, images, engineering drawings, and
other data objects.
7. What are the functions of database server?
The client passes SQL requests as messages to the database server. The results of
each SQL command are returned over the network. The code that processes the SQL
request and the data reside on the same machine. The server uses its own processing
power to find the requested data instead of passing all records back to a client and then
letting it find its own data.
8. What are the functions of a transaction server?
In a transaction server, the client invokes remote procedures that reside on the
server with an SQL database engine. These remote procedures on the server execute a
group of SQL statements. The network exchange consists of a single request/reply
message.
9. Define OLTP.
OLTP-Online Transaction Processing
The client component usually includes a Graphical User Interface (GUI).The
sever component usually consists of SQL transactions against a database. These
applications are called Online Transaction Processing or OLTP.
OLTP applications are mission critical applications that require a 1-3 second
response time 100% of the time and they also require tight controls over the security and
integrity over the database.
10. Define types of OLTP.
Two forms of OLTP are:
TP Lite
TP heavy
TP lite- based on the stored procedures provided by database vendors.
TP heavy- based on the TP monitors provided by OLTP vendors.
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11. Define transaction.
In transaction server, the SQL statements either all succeed or fail as a unit. These
grouped SQL statements are called transactions.
12. Define groupware servers.
Groupware addresses the management of semi-structured information such as
text, image, mail, bulletin boards, and the flow of work. These client/server systems place
people in direct contact with other people.
Example: Lotus Notes
13. Define object servers.
In an object server, the client/server application is written as a set of
communicating objects. Client objects communicate with server objects using an ORB
(Object Request Broker)
14. Define ORB.
ORB-Object Request Broker.
In an object server, client objects communicate with server objects using an ORB
(Object Request Broker).The ORB locates an instance of that object server class, invokes
the requested method, and returns the result to the client object. Server object must
provide support for concurrency and sharing. The ORB brings it all together.
15. This model of client/server consists of thin, portable,”universal” clients that talk
to super fat servers. A web server returns documents when clients ask them by name.
Here the clients and servers communicate using an RPC-like protocol called HTTP.
16. Define middleware.
Middleware is a vague term that covers all distributed software needed to support
interactions between clients and servers. It is software that’s in the middle of the
client/server system.
17. What are the types of middleware?
Types of middleware are:
1. General Middleware
2. Service-specific Middleware
General Middleware:
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General Middleware is the substrate for client/server interactions. It
includes communication stacks, distributed directories, authentication services, network
time, remote procedure calls and queuing services.
Example: DCE, ONC+, Netware
Service –specific middleware:
Service-specific middleware is needed to accomplish a particular client/server type of
service.
Example: Database specific middleware such as ODBC, DRDA, EDA/SQL.
18. Define fat server model.
The fat server model places more function on the server. The examples of fat
server are groupware, transaction, and web servers.
19. Define fat client model.
The fat client model does the reverse of fat server. The examples of fat clients are
database and file servers.
20. Define fat clients.
Fat clients are the most traditional form of client/server. The bulk of application
runs on the client side of equation. Fat clients are used for decision support and personal
software. They provide flexibility and opportunities for creating front end tools that let
end users create their own applications.
21. Define fat servers.
Fat servers applications are easier to manage and deploy on the network because
most of the code runs on the servers. Fat servers try to minimize network interchanges by
creating abstract levels of service.
22. Define 2-Tier client/server architecture.
In 2- tier client/server systems, the application logic is buried inside the user
interface on the client or within the database on the server(or both).examples of 2-tier
client/server systems are file servers and database servers with stored procedures.
23. Define 3-Tier client/server
In 3-tier client/server systems, the application logic(or process) lives in the
middle-tier; it is separated from the data and user interface.3-tier client/server systems are
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more scalable, robust and flexible. Examples of 3 tier client/server systems are TP
monitors, distributed objects and the web.
24. Define intergalactic client/server.
Intergalactic client/server is a new threshold of client/server applications and this
is because of,
1. The exponential increase of low-cost bandwidth on Wide Area Networks - for
example, the Internet and CompuServe.
2. A new generation of network-enabled, multi-threaded desktop operating
systems - for example, OS/2 Warp Connect and Windows 95.
25. What are the basic building blocks of client/server based on situations?
The building blocks of client and server arrangements based on situations are:
Client/server for tiny shops and nomadic tribes.
Client/server for small shops and departments.
Client/server for intergalactic enterprises.
Client/server for a post-scarcity world.
26. What are the building blocks of client/server?
The building blocks of client/server are:
1. The client building block.
2. The server building block.
3. The middleware building block.
27. Define DSM.
DSM-Distributed System Management.
The client runs a component of the distributed system management element.
This could be anything from a simple agent on a managed PC to the entire front-end of
the DSM application on a managing station.
28. Define client building block.
The client building block runs the client side of the application. It runs on the
operating system (OS) that provides graphical user Interface(GUI) or an OOUI (Object
oriented User Interface)that access distributed services, wherever they may be.
28. Define server building block.
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The server building block runs the server side of the application.The server
application typically runs on top of some shrink-wrapped server software package. The
server side depends on the operating system to interface with middleware building block
that brings in the requests for the service.
29. Define middleware building block.
The middleware running block runs both the client and server sides of an
application. It is of three categories: transport stacks, network operating systems (NOSs),
and the service-specific middleware.
30. Define Internet.
The Internet is a worldwide, publicly accessible series of interconnected computer
networks that transmit data by packet switching using the standard Internet Protocol (IP).
It is a “network of networks” that consists of millions of smaller domestic, academic,
business, and government networks, which together carry various information and
services, such as electronic mail, online chat, file transfer, and the interlinked web pages
and other resources of the World Wide Web (WWW).
31. Define Intranet.
An Intranet is a private computer network that uses internet protocols, network
connectivity to securely share part of an organization’s information or operations with its
employees. Sometimes the term refers only to the most visible service, the internal
website.
32. Define extranet.
An extranet is a private network that uses Internet protocols, network
connectivity, and possibly the public telecommunication system to securely share part of
an organization’s information or operations with suppliers, vendors, partners, customers
or other businesses. An extranet can be viewed as part of a company’s Intranet that is
extended to users outside the company (e.g.: normally over the Internet).
33. What are the functions of server program?
The role of server program is to serve multiple clients who have an interest in a
shared resource owned by the server. The typical server does the following functions:
1. Waits for client initiated services.
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2. Executes many request at the same time.
3. Takes care of VIP clients first.
4. Initiates and runs background task activity.
5. Keeps running.
34. Name the types of OS functions on a server.
The types of OS functions are as follows:
1. Base services.
2. Extended services.
35. Define base services.
The base services are a part of standard operating systems. It includes all the basic
operations of an operating system.
36. Define extended services.
The extended services are add-on modular software components that are layered
on top of the base services. Functionally equivalent extended services are provided by
more than one vendor.
37. What are the types of base services?
Types of base services are as follows:
1. Task preemption.
2. Task priority
3. Semaphores.
4. Interprocess communication (IPC)
5. Local/remote Interprocess communication.
6. Threads.
7. Intertask Protection.
8. Multiuser High performance File system.
9. Efficient Memory management.
10. Dynamically linked run-time extensions.
38. Define semaphore.
An operating system must provide simple synchronization mechanisms for
keeping concurrent tasks from bumping into another when accessing shared resources.
These mechanisms are known as semaphores.
39. What are the types of extended services?
1. Ubiquitous communication.
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2. Network Operating system extensions.
3. Binary Large Objects (Blobs)
4. Global directories and Network yellow pages.
5. Authentication and authorization services.
6. System management.
7. Network Time.
8. Database and transaction services.
9. Internet services.
10. Object oriented services.
40. Define thread.
Threads are units of concurrency provided within the single program itself.
Threads are used to create very concurrent, event driven server programs.
41. What is meant by intertask protection?
The operating system must protect tasks from interfering with each other’s
resources. A single task must not be able to bring down the entire system. Protection also
extends to the file system and calls to the operating system.
42. Define BLOBs with examples.
BLOBs-Binary Large Objects.
Images, video, graphics, intelligent documents, database snapshots are BLOBS.
BLOBs are used to test the capabilities of OS, databases and network. Network must
transport BLOBs at astronomic speeds.
43. What are the system management services?
System management services include:
1. Monitoring the performance of all elements.
2. Generating alerts when things break.
3. Distributing and managing software packages on client workstations
4. Checking for viruses and intruders.
5. Metering capabilities for pay –as-you use server resources.
44. What are the object oriented services provided by an OS to a server?
The operating system provides object broker services that allow any object to
interact with any other object across the network. It also provides object interchange
services and object repositories.
45. What are the upper limits of server?
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The limits of servers really depend on the type of service required by their clients.
The safe rule is that clients will always want more services, so scalable servers are
frequently an issue.
46. Define multiservers.
Multiservers (clusters) have more processing power than single server system or
SMP. More servers can be added to increase the processing power (creating a pool of
servers) or existing server can be upgraded to latest generation of PC super server
machines.
46. Define multiprocessing super servers.
Multiprocessing super servers are fully loaded machines and they have
multiprocessors, high speed disk arrays for intensive I/O and fault tolerant services. It is
of two types namely:
1. Asymmetric multiprocessing
2. Symmetric multiprocessing.
47. Define asymmetric multiprocessing superservers.
Asymmetric multiprocessing superservers impose hierarchy and a division of
labor among processors. Only one designated processor, the master can run the operating
system at any time. The master controls the slave processors dedicated to specific
functions such as disk I/ or network I/O.
48. Define symmetric multiprocessing superservers.
Symmetric Multiprocessing treats all processors equals. Any processor can do the
work of any other processor. It improves performance and throughput of the server
system.
49. Define co-processor.
A coprocessor is an extreme form of codependency; one processor completely
controls a slave processor through interlocked special –purpose instructions. The
coprocessor has unique special purpose hardware that is not identical to the main
processor.
50. What are the three categories of clients?
The three categories of clients are:
1. Non-GUL clients.
2. GUI clients.
3. OOUI clients.
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51. Defline Non-GUI clients.
Non-GUI client applications generate requests with a minimal amount of human
interaction. GUI clients are of two types:
1. Non-GUI clients that do not need multitasking:
These clients may provide a simple human interface in the request
generation loop.
Examples:
Automatic Teller Machines (ATM), barcode readers,
cellular phones, fax machines, smart gas pumps, and intelligent
clipboards.
52. Non GUI clients that need multitasking:
These clients often require very granular, real-time, event driven
multitasking services.
Examples: robots, testers, and daemon programs.
53. Define GUI clients.
Simple GUI clients are applications where occasional requests to the server
results from a human interacting with GUI. These clients are good for mainstream, OLTP
business applications with repetitive tasks and high volumes.
54. Define OOUI clients.
Object Oriented User Interface (OOUI) clients are highly iconic and provides
object oriented user interface access to information in visual formats. They are used by
information workers doing variable, multiple tasks whose sequence cannot be predicted.
55. What are the examples of OOUI client?
The examples for OOUI clients are:
1. Executive and decision support systems.
2. Multimedia based training systems.
3. System management consoles.
4. Stock broker workstations.
56. Define modeless dialogs.
In OOUI clients, the desktop can contain multiple workplaces running
concurrently. Each workplace may be running parallel dialogs, also called modeless
dialogs, over parallel sessions with the server.
57. What are the compound documents frameworks?
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Compound document framework includes,
1. OLE
2. OpenDoc
OLE and OpenDoc forms the latest and greatest OOUI technology
58. Define OLE.
OLE-Object Linking and Embedding
OLE is a part of Windows 95; it provides the component foundation of
Microsoft’s desktop, enterprise and Internet/Intranet products.
59. Define shippable places.
A shippable place is a mobile container of components; it’s a place that can be
shipped over the net. Shippable places let you interact with multiple places that represent
collaborative environments based on real-world; it’s like having multiple desktops.
60. Define place.
A place is a visual ensemble of related components. It is also a mini virtual world
that servers can ship to their clients.
66. What are the client OS trends?
The client OS trends are:
1. The desktop is becoming more fragmented.
2. The web will generate a huge demand for documents.
3. There will be huge demand for fat PC’s.
4. Shippable places will become new desktops.
5. Embedded clients will be everywhere.
67. What are the cons of MAC OS?
1. Mac OS is not a very good server platform.
2. It does not scale well and has limited multithreading options.
3. It is also not a good advanced client platform.
68. What are the cons of Windows 95?
1. Windows 95 OOUI is inconsistent.
2. Mixes GUI and OOUI paradigms.
3. Still built on DOS;
4. Not robust for corporate client market.
69. What are the features of Windows NT workstation?
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1. Windows NT workstation is a robust 32-bit client OS. It supports preemptive
multitasking, multithreading, memory protection and a transactional file system.
2. Network ready supports TCP/IP, NetBEUI, IPX/SPX, PPP and AppleTalk.
3. Provides C-2 level securities.
70. What are the cons of Windows NT?
1. NT workstation is a resource hog. It requires minimum of 16Mbytes RAM and
512 Mbytes (disk).
2. Support for laptop is poor.
3. Limited PCMCIA support and power management.
4. Does not support virtual device drivers.
5. Does not support plug and play.
6. Expensive client platform.
7. Does not get the same level of ISV support as the rest of the windows platform.
71. What are the cons of NT server?
1. NT server does not scale well.
2. Addition of processor makes it slow
3. Does not provide an enterprise directory server; does not even integrate with
other back office applications.
4. Back up facilities are not good.
5. Have security holes.
72. What are the features of OS/2 warp server?
1. OS/2 is an excellent application server.
32-bit Operating system incubates leading edge server software including
2. LotusNotes and CORBA services.
3. Auto detects hardware, easier to find and configure network adapters.
4. Provides disk mirroring, remote administration, remote software distribution, a
back server, software metering.
73. What are the cons of OS/2 warp server?
1. OS/2 is an Intel-only server platform.
2. OS/2 does not incur the extra burden of a portability layer.
74. Define transparency.
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Transparency means fooling everyone into thinking the client/server system is
totally seamless. It really means hiding the network and its servers from the users and
even application programmers. It is referred as “network disappearing act”.
75. What are the types of transparency?
Location transparency
Namespace transparency
Logon transparency
Replication transparency
Local/remote transparency
Distributed transparency
Failure transparency
Administration transparency
76. What are the types of synchronization schemes used to refresh replicas in global
directory?
The two types of synchronization schemes used to refresh replicas include:
Immediate replication
Skulking
Immediate replication:
This causes any update to the master to be immediately shadowed on all
replicas.
Skulking:
This causes a periodic propagation (for example, once a day) to all the
replicas of all changes made on the master.
77 . What are the techniques involved in distributed time services?
The two techniques involved in distributed time services are:
1. It periodically synchronizes the clocks on every machine in the
network.
2. It introduces an inaccuracy component to compensate for unequal clock
drifts that occur between synchronizations.
78. Define encryption.
Encryption allows two principals to hold a secure communication. Each principal
must obtain a copy of a session key from a trusted third party. This session key can be
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used for encoding and decoding messages. Another approach is to use a public, private
key encryption technique.
79. Define cryptographic checksums.
Cryptographic checksum is a less extreme solution that ensures data is not
modified as it passes through the network. The sender calculates a checksum on the data,
using a session key to encrypt it, and appends the result to the message. The receiver
recalculates the checksum, decrypts the one received in the message using the session
key, and then compares the two.
80. Define socket.
A socket is one end of a two-way communications link between two programs
running on the network. Sockets are supported on virtually every operating system.
81. Define WinSock.
The windows socket API is known as Winsock, which is a multivendor
specification that standardizes the use of TCP/IP under windows. The Winsock API is
based on the Berkeley sockets interface.
82. Define socket address.
A socket address on the TCP/IP consists of two parts: an internet address
(IP_address) and a port number.
Socket address=internet address (IP) +port address.
Internet address is a 32-bit integer usually represented by four decimal numbers
separated by dots that must be unique for each TCP/IP network interface card.
Port address is represented by 16- bit integer.
83. Define port.
A port is an entry point to an application that resides on a host. It is represented by
a 16-bit integer. Ports are commonly used to define the entry points for services provided
by server applications.
12. What are the popular socket types?
The three most popular socket types are:
Stream
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Datagram
Raw
Stream and datagram sockets interface to the TCP and UDP protocols
Raw sockets interface to the IP protocol.
84. Define connection oriented protocol.
Connection-oriented protocols-also known as session –based protocols, virtual
circuits, or sequenced packet exchanges provide a reliable two-way connection service
over a session. Each packet of information that gets exchanged over a session is given a
unique sequence number through which it gets tracked individually acknowledged.
Duplicate packages are detected and discarded by the session services.
85. Define IPX protocol.
The IPX/SPX network layer is provided by the Internet packet Exchange (IPX)
protocol. This is a “send and pray” datagram protocol with no guarantees. It is used as a
foundation protocol by sophisticated network applications for sending and receiving low-
overhead datagram packets.
86. Define SPX protocol.
The transport layer of IPX/SPX is provided by the sequenced packet exchange
(SPX) protocol which is responsible for a reliable connection oriented service over IPX.
This service consists of 16 API calls.
87. Define NETBIOS protocol.
NETBIOS is the premier protocol for LAN based program-to-program
communications. NetBIOS is used as an interface to a variety of stacks-including
IBM/Microsoft LANs (NetBEUI), TCP/IP, XNS, Vines, OSI, and IPX/SPX. Support for
a NetBIOS platform exists on a multiplicity of operating system environments, including
MS-DOS, Windows, Windows95, OS/2, Window NT, UNIX, and some mainframe
environments. One of the many reasons for NetBIOS success is its intuitive simplicity.
88. Define NETBEUI protocol.
NetBEUI is the protocol stack that comes with IBM and Microsoft LAN products
including Windows for Workgroups, NT, LAN Manager, Windows 95, OS/2 Warp
Connect, and OS/2 Warp Server. It came to life as the original transport for NetBIOS
commands.
89. Define RPC.
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RPC-Remote Procedure Call
RPC like an ordinary procedure call is synchronous. A client process calls a
function on a remote server and suspends itself until it gets back the results. Parameters
are passed like in any ordinary procedure.
90. What are the issues faced in RPC?
The issues in RPC are:
How are the servers functions located and started?
How are parameters defined and passed between the client and the server?
How are failures handled?
How is security handled by RPC?
How does the client find its server?
How is data representation across systems handled?
91. Define IDL.
IDL-Interface Definition Language
IDL (Interface Definition Language) describes the functions and parameters that a
server exports to its clients. An IDL complier takes these descriptions and produces
source code stubs (and header files) for both client and server.
92. Define binding.
The association of a client with a server is called binding. The binding
information can be hard coded in the client or a client can find its server by consulting a
configuration file or an environment parameter.
93. Define automatic binding and dynamic binding.
The process of using a directory to find a server at runtime is called dynamic
binding.
The easiest way of finding a server with the help of RPC is called automatic
binding, where the RPC client stub will locate a server from a list of servers that
supports the interface.
94. Define MOM.
MOM-Message Oriented Middleware
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MOM is a key piece of middleware that is absolutely essential for a class of
client/server products. MOM allows general purpose messages to be exchanged in a
client/server system using message queues.
95. Define persistent and non persistent message queues.
Persistent (logged on disk) messages are slower and they can be recovered in case
of power failures after a system restart.
Non Persistent messages refer to message queues in memory.
In both the cases messages can be copied or removed from a queue.
96. Differences between MOM and RPC.
Features MOM: Messaging and
Queuing
RPC: Remote procedure call
Metaphor Post office-like Telephone- like
Client/server relationship
Asynchronous. Clients and
servers operate at different
times and speed.
Synchronous. Client and
server must run concurrently.
Client/server sequencing No fixed sequence Servers must come up before
clients can talk to them.
Style Queued Call-Return
97. Define Kerberos.
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Kerberos is the trusted third party that allows to processes to prove to each other
that they are who they claims to be. Kerberos authentication system is widely
implemented in distributed Computing Environment (DCE).
26. Define ACL (Access Control List)
Servers use access control list (ACLs) to control user access. ACLs can be
associated with any computer resource. They contain list of names and the type of
operations they are permitted to perform on each resource.
98. Define DFS.
DFS-Distributed File System
DFS provides a single image file system that can be distributed across a group of
file servers. The DFS file naming scheme is location independent. Each file has a unique
identifier that is consistent across network.
99. Define DCE cell.
DCE divides the distributed environment into administrative units (or domains)
called cells. A DCE cell is a combination of client and server workstations.
A cell usually consists of the set of machines used by one or more groups working on
related tasks. A DCE cell must have one directory server and one security server.
100. Name the elements of DCE directory services.
DCE directory services consist of:
Cell directory services (CDS)
Global directory services (GDS)
This two tier hierarchy provides local naming autonomy (at the cell level) and global
interoperability (at the inter cell level).
101. Define Authentication.
Authentication validates a client, typically a user or program is who or what it
claims to be. In time shared systems, the authentication is done by the OS using
passwords.DCE implements authentication by Kerberos.
102. Define Authorization.
Authorization comes after authentication; it determines whether the authenticated
client has permission to access a resource. DCE supports authorization through Access
Control List (ACLs).
103. Define DCE threads package.
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The DCE thread package provides granular levels of multitasking on operating
systems that do not provide multitasking threads.DCE thread packages support
multitasking environments using shared memory.DCE provides a semaphore service that
helps threads synchronize their access to shared memory.
104. What are the names of protocol introduced by Netscape navigator?
SSL(Secure Socket Layer)
S-HTTP(Secure –HTTP)
Firewalls
105. Define CGI.
CGI-Common Gateway Interface
CGI is now being used to access every known server environment .
CGI is a standard for interfacing external applications with information servers, such as
HTTP or Web servers.
106. Define Hypertext.
Hypertext is a software mechanism that links documents to other related
documents on the same machine or across networks. The linked document can itself
contains links to other documents, and this can go on forever. A link can also point to
other external resources such as image files, sound clips or executable programs.
107. Give some example for Internet Application Protocols.
Simple Mail Transfer Protocol(SMTP)
File Transfer Protocol(FTP)
Network News Transfer Protocol(NNTP)
Gopher
108. Define URL.
URL-Unified Resource Locator.
URL protocol provides a consistent intergalactic naming scheme to identify all
web resources-including documents, images, sound clips and programs.
109. Define HTTP
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HTTP-Hypertext Transfer Protocol
The web provides an RPC like protocol called the HTTP for accessing
resources that live in URL space. HTTP stateless RPC that
1) Establishes a client/server connection
2) Transmits and receives parameters including a returned file
3) Breaks the client/connection
110. Why web browsers are referred as ‘Universal clients’?
A web browser is a minimalist client that interprets information it receives from a
server, and displays it graphically to user. The client is simply there to interpret the
server’s commands and render the contents of an HTML page to an user.
111. What are the steps involved in client/server interaction?
1. Select a target URL
2. Browser sends an HTPP request to server
3. Server comes to life and processes the request
4. Browser interprets the HTML commands and displays the page
contents.
112. What are parts of the URL?
The parts of URL include:
1) The protocol scheme-It tells the web browser which internet protocol to
use when accessing a resource on a server.
2) The server name-It is usually an internet host domain name that
identifies the site on which the server is running.
3) The port number-It identifies a program that runs on a particular server.
4) The path to a target resource-It starts with the slash after the host and
the port number.
Ex: http://www.address.com:7800:/path/subdir/file.ext
113. Give some examples for tags in HTML?
<B>Bold</B>
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<I>Italic</I>
<U>Underlined</U>
<TT>Fixed-window</TT>
<STRIKE>strike out</STRIKE>
114. What is mean by tags in HTML?
The tags are non-case sensitive commands surrounded by angle brackets. A tag
pair consists of a command, then some text and finally the inverse command –represented
as the command with a slash in front of it.
115. Write a HTML program to show about the heading tags.
<HTML>
<HEAD>
<TITLE> My DOCUMENT</TITLE>
</HEAD
<BODY>
<H1>THIS IS AN H1 HEADING</H1>
<H2> THIS IS AN H1 HEADING</H2>
<H3> THIS IS AN H1 HEADING</H3>
<H4> THIS IS AN H1 HEADING</H4>
<H5> THIS IS AN H1 HEADING</H5>
<H6> THIS IS AN H1 HEADING</H6>
</BODY>
</HTML>
116. Write few HTML tags for creating list.
HTML tags for creating unordered list:
<UL>
</UL>
HTML tags for creating ordered list:
<OL>
</OL>
117. Write HTML tag to include images in the document.
HTML tag for including image in a document is given by,
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< IMG SRC=”file.zif”>
This tag includes an attribute called SRC that contain the URL of the external
picture file or the name of a local file.
118. Define Hyperlinks.
Hyperlinks are used to link our document to other documents or to other locations
in the same document using a pair of anchor tags that look like this:
<A HREF=”Target URL”>
This is good link
</A>
119. Give some versions of HTML.
There are different versions of HTML. The following are some examples:
HTML 1.0
HTML 2.0
HTML 3.0(originally known as HTML+)
120. Define HTTP.
HTTP- Hypertext Transfer Protocol.
HTTP is used to access and retrieve URL-named resources. The HTTP
RPC is stateless. The client establishes a connection to the remote server, then
issues a request. The server then processes the request, returns a response, and
closes the connection.
121. Give HTTP request syntax.
HTTP request consists of a request line, one or more optional request
header fields, and an optional entity body.
122. Give HTTP response syntax.
HTTP response consists of a response header line, one or more optional
response header fields and an optional entity body.
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123. What are the steps involved in CGI scenario?
1. User clicks on the form’s “submit” button.
2. The web browser invokes a POST HTTP METHOD.
3. The HTTP server receives the method invocation via a socket connection.
4. The HTTP server sets up the environmental variables.
5. The HTTP server starts a CGI program.
6. The CGI program reads the environmental variable.
7. The CGI program receives the message body via the standard input pipe(stdin).
8. The CGI program does some work.
9. The CGI program returns the results via the standard output pipe(stdout)
10. The HTTP server returns the results to the web browser.
124. What are the uses of environmental variables?
In order to pass data from the server to the script, the server uses command line
arguments along with environment variables.
The Environment Variables are set when the server executes a CGI Script.
Environment Variables allow the CGI Script to reference variables that might be
wanted for the Script output.
125. Give some examples for environmental variables.
The examples of environmental variables are:
SERVER_NAME
– The server's Host name or IP address
SERVER_SOFTWARE
– The name and version of the server-software that is answering
the client requests
SERVER_PROTOCOL
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– The name and revision of the information protocol the request
came in with.
REQUEST_METHOD
– The method with which the information request was issued.
126. Define SQL.
SQL-Structured Query Language.
SQL is a standard language for accessing and manipulating databases.SQL (Structured
Query Language) is a database computer language designed for the retrieval and
management of data in relational database management systems (RDBMS), database
schema creation and modification, and database object access control .management.
127. What are the features of SQL?
SQL has the following features:
1. SQL is an interactive query language.
2. SQL is a database programming language.
3. SQL is a data definition and data administration language.
4. SQL is the language of networked database servers.
5. SQL helps protect the data in a multi-user networked environment.
128. Mention few ISO standards of SQL.
ISO standards of SQL are:
SQL-89
SQL-92(also called SQL2)
SQL-3
129. What are the SQL database architectures?
There are three SQL database architectures namely:
Process-per-client architecture.
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1. Multithreaded architecture.
2. Hybrid architecture.
130. Define stored procedure.
A stored procedure is a named collection of SQL statements and procedural logic
that is complied, verified, and stored in the server database. Stored procedure is typically
treated like any other database object and registered in the SQL catalog.
131. Define static SQL.
Static SQL statements are defined in code and converted into an access plan at
program preparation time. The SQL statement is known before program is running.
132. Define dynamic SQL.
Dynamic SQL statements are created and issued at run time. They offer maximum
flexibility at the expense of execution speed. Dynamic SQL is an interpretive form of the
SQL language.
133. Define Trigger.
Triggers are special user-defined functions usually in the form of stored
procedures that are automatically invoked by the server based on data-related events.
Triggers can perform complex actions and can use the full power of a procedural
language.
132. Define rule.
A rule is a special type of trigger that is used to perform simple checks on data.
Rules are attached to specific operations on specific tables.
133. Mention two SQL middleware options.
The SQL middleware options include:
SQL nirvana: The single vendor operation.
SQL nightmare: The multivendor operation.
134. Define OLTP.
OLTP (online transaction processing) is a class of program that facilitates and
manages transaction-oriented applications, typically for data entry and retrieval
transactions in a number of industries, including banking, airlines, mail order,
supermarkets, and manufacturers.
135. Define DSS.
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Decision Support Systems (DSS) are used to analyze data and create reports.
They provide the business professional and information hounds with means to obtain
exactly the information they need. A successful decision-support system must provide
user with flexible access to data and the tools to manipulate and present that data in all
kinds of report formats.
136. Define EIS.
Executive Information Systems (EIS) are powerful, easy-to-use, and business
specific than DSS tools. They are certainly more expensive, which may explain why the
“executive” attribute is in the name.
137. Define data warehouse.
Data warehouse is a central repository for all or significant parts of the data that
an enterprise's various business systems collect. The term was coined by W. H. Inmon.
IBM sometimes uses the term "information warehouse."Richard Hack thorn defines
warehouse as “a collection of data objects that have been inventoried for distribution
to a business community”.
138. What are the elements of data warehousing?
Data warehousing includes four elements:
The data replication manager
1. The informational database.
2. The information directory.
3. EIS/DSS tool support.
139. Define OLAP.
Online Analytical Processing, a category of software tools that provides analysis
of data stored in a database. OLAP tools enable users to analyze different dimensions of
multidimensional data. For example, it provides time series and trend analysis views.
OLAP often is used in data mining.
140. Define data mining.
Data mining, the extraction of hidden predictive information from large databases,
is a powerful new technology with great potential to help companies focus on the most
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important information in their data warehouses. Data mining tools predict future trends
and behaviors, allowing businesses to make proactive, knowledge-driven decisions.
141. Mention some data mining tools.
Associations
Sequential pattern.
Clustering.
142. Define Association.
Associations look for patterns where the presence of something implies the
presence of something else.
Example: Scuba gear buyers are candidates for Australian vacations.
143. Define sequential patterns.
Sequential patterns look for chronological occurrences.
Example: When the price of stock goes up by 10%,the price of stock Y goes by
15% a week later.
144. Define clustering.
Clustering looks for groupings and high-level classifications.
Example: Over 70% of undecided voters have incomes of over $60,000,age
brackets between 40 and 50 and live in XYZ neighborhood”.
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