It is possible. I think it is called as side by side 
execution. But i don't konow the code. If any one know 
please write.

Off course Krishna is right it is called as side by side 
execution
<Configuration>
<runtime>
<assemblyIdentity name="ABCD" publicKeyToken="Sometoken"
culture="neutral" />

<bindingRedirect
oldVersion="1.0.0.0-99999.99999.99999.99999"
newVersion="1.0.1445.38584" />

<codeBase version="1.0.1445.38584" href="C:\Program
Files\TPA\ABCD.dll" />

</dependentAssembly>
</runtime>
<Configuration>

i think oldb is not correct it's may b.
it is oledb

using system.data.oledb;
oledbconnection cn=new
oledbconnection("uid=<username>;pwd=<password>;server=<servername>");
cn.open();

it is not oldb it may be oledb

using System.Data.Oledb;

Oledbconnection cn=new OleDbConnection
("Provider=Msdaora.1;uid=<username>;pwd=<pwd>;server=<server
name>");
cn.open();

yes we can use 'throw' or new Exception.

the 'try' block contains the code which may have the 
runtime errors. to handle that errors we use 'catch' block.

We can throw exception in catch block 

Like

try
{
int a=10/0;
}
catch(Exception ex)
{
throw ex;
}

try - catch - finally.  Catch most specific exceptions 
first.

Serialization is the process of saving the state of an 
object by converting it to a stream of bytes

serialization is process of converting object into stream

Serialization is a process of converting object into stream
of bytes.

Types of Serialization 

1)XML Serialization
2)SOAP Serialization
3)Binary Serialization
4)Custom Serialization

In XML Serialization we can convert only public objects into
stream of bytes, where as in SOAP and Binary Serialization
we can convert private objects also. 

In XML Serialization we can able to convert only objects
into stream of bytes, but in Binary Serialization we can
convert all the objects(Objects in Object) also.

SERIALIZATION:
            serialization is the process of converting an 
object or a graph of object in to a linear sequence of 
bytes or stream.

All the above descriptions are corret.

Seriallization is done for the faster accessing of remote 
object. So it is mainly used in remoting. 
Remoting is a concept in .Net which helps to access/make 
use of remote (through internet) application(/object).
So the object requested is converted in to stream of bytes 
and get transfered to the requsted application.

Dataset.copy method copies both the structure and data 

 Clone just copy the structure of dataset

Execute non Query is used to execute more than one command 
at the time (it is used for insert ,delete ,update)

this method is invoked whenever DMLcommands has 
beenexcecuted

it returns the no. of queries executed successfully

Execute Non Query(),is for insert,delete and update...
i.e for the statements which does'nt returns any value after
the execution.

Execute NOn Query

Execute Non uery is used to perform catalog operations(i.e. 
creating databse objcts such as tables) or to change the 
data in database  without using a dataset by executing 
update, Insert and Delete operations.

it returns no of records updated and will be used for inert,
delete and updated operations

This method belongs to connection object.We call this 
method to indicate that the stored procedure doesn't return 
results for a query but rather than an integer indicating 
how many rows are effected by the executed statement.

EXECUTE NON QUERY IS COMMAND OBJECT METHOD USED TO 
INSRET,DELETE,UPADTE DATA INTO A DATABASE

Scalar will return only one value.
(ie we can read or write only one data at the time)

When we want any aggreagate answer then we use execute 
scaler examples like avg,sum etc
this return one row and one column

It Returns Single Scalar value as a result

This method is used to execute commands that return single 
value rather than resultset.

when we want to retrieve data that has single value then we
can prefer to execute scalar.

execute scalar return a object type value, by defalut it 
will return first row of fst column value, mostly we used 
it with aggregate function like sum(),max(),min(),avg()....

It is use to free the memory of the object r method in use.

leakage memory of unused and unreferenced objects

it is clr function 
it is use to release those objext whitc is not longer useor 
no longer refeances in application 

it is System.GC.Collaction

garbage collection is the process of clearing the memory of 
unused objects, which will be taken care by CLR on 
periodical basis.

Actually the new operater is used to allocate the memory to 
an object that object not needed for longtime,so that 
objects are thrown away or release from the memory by the 
garbage collector.

Ofcourse, Garbage Collection is done for the memory 
utilization (making use of memory space which is allocated 
to the unused objects).
And this Garbage Collection is autometically done by the 
CLR. Still we can also implicity for the CLR to collect the 
unused memory allocated to unused objects. But that is not 
at all necessary.

When a program is loaded into memory, it is organized into 
three areas of memory, called segments: the text segment, 
stack segment, and heap segment.
So the compiled code will reside in the text segment.
the variables like string, int ect..(value types) will 
reside in stack segment.
the objects like class(reference type) will reside in the 
heap segment.
So when a new object is created the Garbage Collector will 
look unused objects and it will free them from the heap. so 
that the new object can reuse the memory allocated to the 
unused object.

I think yes.. Function can return multiple values.. It's 
not good practice.. but C# allows you.. Consider following 
example

int Val;
GetValue(Val);

bool GetValue(out int Val)
    {
        Val = value;
        return true; 
    }

yes.
for example:
public int Add(int a,int b,out int c)
{
c=a+1;
return a+b;
}
when we call the Add method we will get the sum of the a 
and b and can also use the value of c
like
int d=0;
int e= Add(2,3,d) ;
then the value of e will be 5 and the value of d will be 3.

with the help of out paraeter we can return two value from
function

in c# a function can return two values  with the help of out
parameter.

Guys, you will be able to return n number of values, while 
you are using arraylist.

No. not at all. well that's the main difference between
functions and procedures. A function can return one n only
one value. We can write only one return statement and only
only return type.

yes we can return two values with the help of out keyword

No
only one value will return at a time but function may have 
multiple output statement ..

just use recursive function call...

this is the concept used to develop multi language 
applications in a project

Both are system resources

Globalization is the process of designing and developing 
applications that function for multiple cultures.

Localization is the process of customizing your application 
for a given culture and locale.

asp.net supports 2 types of sessions
inprocess:session maintained by application domain[default]

outprocess:session maintained outside application
domainexternal to worker process.the external process can be:-

(i)state server:is a service of o/s which comes with .net
installation.this supports temopary storage.           

(ii)sqlserver:persistent storage is supported.

(iii)custom:requires manual coding

cookieless session:it is a concept of providing sessionid to
client by appending to url.

Four Types of Session Types-

1. InProc mode- which stores session state in memory on the 
Web server. This is the default.
2.StateServer mode- which stores session state in a 
separate process called the ASP.NET state service. This 
ensures that session state is preserved if the Web 
application is restarted and also makes session state 
available to multiple Web servers in a Web farm.

3.SQLServer mode- stores session state in a SQL Server 
database. This ensures that session state is preserved if 
the Web application is restarted and also makes session 
state available to multiple Web servers in a Web farm.

4.Custom mode- which enables you to specify a custom 
storage provider.

5. Off mode- which disables session state.

i think it's oledb may b.

in c#.net coding

1)
using oledd provider
1.system.data.oledb;
2.oledbconnection cn=new
oledbconnection("username=<username>;pwd=<password>;server=<servername>");
3.cn.open();

2)
using orcale provider
1.first u can give in u r application reference of
system.data.orcaleclient.dll file trough solutionexplorer of
u r application
(rt click the mouse--->over solutinexplorer--->and click add
reference--->click on project---> and select
system.data.orcaleclient.dll file--->ok  )
2.using system.data.orcaleclient;
3.orcaleconnection cn=new
orcaleconnection("username=<username>;pwd=<password>;server=<servername>");
3.cn.open();

click on solution explorer window right click and add to 
add new item. the window will be displaded select the 
crystal report we have save in any name but extensen is 
used .rpt eg:sss.rpt

using CrystalDecison.Shared namespace

using CrystalDecisions.Shared;(name Space
using CrystalDecisions.CrystalReports.Engine;(name space)