alternative to SELECT DISTINCT

SELECT with GROUP BY can be used as an alternative to SELECT DISTINCT. Pranay Rana's example is essentially equivalent to

SELECT DISTINCT UserName, Departmentid FROM user

If you want an example where the preference of GROUP BY over DISTINCT is justified, here's one. Say, you want to return items that only occur once in a table:

SELECT Item
FROM atable
GROUP BY Item
HAVING COUNT(*) = 1




Object Pooling

It is a concept that implies that we can store a pool of objects in memory to be reused later and, hence, reduce the load of object creation to a great extent. An Object Pool, also known as a Resource Pool, is a list/set of ready to be used reusable objects that reduce the overhead of creating each object from the scratch whenever a request for an object creation comes in.The biggest advantage of using Object Pooling is that it minimizes the consumption of memory and the system's resources by recycling and re-using objects as and when it is needed and serving the request for new objects from the pool of ready-to-be-used objects. The objects that the application is done with (the objects are no longer needed) are sent back to the pool rather than destroying them from the memory

What's the result : Select 3/5

It will 0, Select do the mathematical operation, but it returns 0 , if Numerator is less than  denominator

Object Pooling

It is a concept that implies that we can store a pool of objects in memory to be reused later and, hence, reduce the load of object creation to a great extent. An Object Pool, also known as a Resource Pool, is a list/set of ready to be used reusable objects that reduce the overhead of creating each object from the scratch whenever a request for an object creation comes in.The biggest advantage of using Object Pooling is that it minimizes the consumption of memory and the system's resources by recycling and re-using objects as and when it is needed and serving the request for new objects from the pool of ready-to-be-used objects. The objects that the application is done with (the objects are no longer needed) are sent back to the pool rather than destroying them from the memory

Staging Server

A Staging server, which might house untested and , indeed, broken components , the files served by a production server are generally assumed to have undergone extensive testing.

Production Server

A production server is a web server that delivers what is often called the "live site". It is typically available to the entire web and house that most recent version of its respective site