Interview Questions

GROUP BY partitions the selected rows on the distinct values of the column on which you group by. HAVING selects GROUPs which match the criteria specified

- A web page with large number of images takes a longer time to load. This is because each image separately sends out a http request.

- The concept of CSS sprite helps in reducing this loading time for a web page by combining various small images into one image. This reduces the numbers of http request and hence the loading time.

When a class is derived from another class, then the members of the base class become the members of the derived class. The access modifier used while accessing members of the base class specifies the access status of the base class members inside the derived class.

The syntax to inherit a class from another class in C# is as follows:
class MyNewClass : MyBaseclass

When ever two or more threads are sharing same data for updating then unpredicted result will be there in the data.

For Example take a thread is depositing amount in Account Object and another thread is withdrawing amount from the same Account Object.

when ever both threads are executed simultaneously then unexpected result is stored in the balance of the  Account Object. 

- A clustered index is a special type of index that reorders the way records in the table are physically stored. Therefore table can have only one clustered index. The leaf nodes of a clustered index contain the data pages.

- A non clustered index is a special type of index in which the logical order of the index does not match the physical stored order of the rows on disk. The leaf node of a non clustered index does not consist of the data pages. Instead, the leaf nodes contain index rows.

A sequence is a database object that is used to generate sequential number.

CREATE SEQUENCE seqname [increment] [minimum value][maximum value][start][cache][cycle]               Nextval and currval lets us get the next value and current value from the sequence.