What is Structured Query Language (SQL)?
SQL is a powerful set-oriented language which was developed by IBM
research for the databases that adhere to the relational model. It
consists of a short list of powerful, yet highly flexible, commands that
can be used to manipulate information collected in tables. Through SQL,
we can manipulate and control sets of records at a time.
What is Remote Procedure Call (RPC)?
RPC hides the intricacies of the network by using the ordinary procedure
call mechanism familiar to every programmer. 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. The RPC,
like an ordinary procedure, is synchronous. The process that issues the
call waits until it gets the results.
Under the covers, the RPC run-time software collects values for the
parameters, forms a message, and sends it to the remote server. The
server receives the request, unpack the parameters, calls the
procedures, and sends the reply back to the client. It is a
What are the main components of Transaction-based Systems?
Transaction Manager and
What are the three types of SQL database server architecture?
Process-per-client Architecture. (Example: Oracle 6, Informix )
Multithreaded Architecture. (Example: Sybase, SQL server)
What are the Classification of clients?
Non-GUI clients - Two types are:-
Non-GUI clients that do not need multi-tasking
(Example: Automatic Teller Machines (ATM), Cell phone)
Non-GUI clients that need multi-tasking
What are called Non-GUI clients, GUI Clients and OOUI Clients?
Non-GUI Client: These are applications, generate server requests with a
minimal amount of human interaction.
GUI Clients: These are applications, where occasional requests to the
server result from a human interacting with a GUI
(Example: Windows 3.x, NT 3.5)
OOUI clients : These are applications, which are highly-iconic,
object-oriented user interface that provides seamless access to
information in very visual formats.
(Example: MAC OS, Windows 95, NT 4.0)
What is Message Oriented Middleware (MOM)?
MOM allows general purpose messages to be exchanged in a Client/Server
system using message queues. Applications communicate over networks by
simply putting messages in the queues and getting messages from queues.
It typically provides a very simple high level APIs to its services.
MOM's messaging and queuing allow clients and servers to communicate
across a network without being linked by a private, dedicated, logical
connection. The clients and server can run at different times. It is a
post-office like metaphor.
What is meant by Middleware?
Middleware is a distributed software needed to support interaction
between clients and servers. In short, it is the software that is in the
middle of the Client/Server systems and it acts as a bridge between the
clients and servers. It starts with the API set on the client side that
is used to invoke a service and it covers the transmission of the
request over the network and the resulting response.
It neither includes the software that provides the actual service - that
is in the servers domain nor the user interface or the application login
- that's in clients domain.
What are the functions of the typical server program?
It waits for client-initiated requests. Executes many requests at the
same time. Takes care of VIP clients first. Initiates and runs
background task activity. Keeps running. Grown bigger and faster.
What is meant by Symmetric Multiprocessing (SMP)?
It treats all processors as equal. Any processor can do the work of any
other processor. Applications are divided into threads that can run
concurrently on any available processor. Any processor in the pool can
run the OS kernel and execute user-written threads.
What are General Middleware?
It includes the communication stacks, distributed directories,
authentication services, network time, RPC, Queuing services along with
the network OS extensions such as the distributed file and print
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