Technology Questions

DB2 use the multiple indexes to satisfy multiple predicates in a SELECT statement that are joined by an AND or OR.

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

I/O operations like reading or writing a file is not possible with client-side javascript. However , this can be done by coding a Java applet that reads files for the script. 

Validation controls are responsible to validate the data of an input control. Whenever you provide any input to an application, it performs the validation and displays an error message to user, in case the validation fails.

ASP.NET 4.0 contains the following six types of validation controls:

   => CompareValidator - Performs a comparison between the values contained in two controls.
   => CustomValidator - Writes your own method to perform extra validation.
   => RangeValidator- Checks value according to the range of value.
   => RegularExpressionValidator - Ensures that input is according to the specified pattern or not.
   =>  RequiredFieldValidator - Checks either a control is empty or not.
   => ValidationSummary - Displays a summary of all validation error in a central location.

In a correlated query, the outer query is related to the inner query. This means one or more columns in the outer query are referenced. It’s used when the outer queries value is being used by inner query. For example, we need to find which employee had more perks in the current month than they did in the previous month. The correlated subquery is executed for each row of perks information in the parent query to first determine what the perks were for each employee in the previous month. This data, in turn, is compared to perks for each employee in the current month, and only those employees whose perks in the current month were greater that their previous month's perks are returned.

They are DEFINE CLUSTER, DATA and INDEX.

TDD is an acronym for Test-Driven Development. TDD is a software development process that relies on the repetition of a very short development cycle: first the developer writes an (initially failing) automated test case that defines a desired improvement or new function, then produces the minimum amount of code to pass that test.

TDD is an iterative software development process where you first write the test with the idea that it must fail.

This is a different approach to the traditional development where you write the application functionality first andthen write test cases. The major benefit of this approach is that the code becomes thoroughly unit tested (you canuse JUnit or other unit testing frameworks).