Interview Questions

Primary key constraint ensures that the column(s) always has a unique value to identify the record.
Example:
Below, the primary key is created for column id with name prim_id.
create table employee ( id number NOT NULL, Name varchar(200) Constraint prim_id primary key(id) );

Layer objects are data objects which represent visual content. Layer objects are used by views to render their content. Custom layer objects can also be added to the interface to implement complex animations and other types of sophisticated visual effects.

Regression Testing: When changes in the code of the software are made to fix the previous bug. Then testing needs to be perform to ensure that it will not generate a new bug in the application and it works as specified and that it has not negatively impacted any functionality that it offered previously. Regression Testing is important because of following reason:

- That the application works even after the alteration in the code were made.

- The original functionality continues to work as specified even after doing changes in the software application.

- The alteration to the software application has not introduced any new bugs.

Notices: These are trivial, non-critical errors that PHP encounters while executing a script - for example, accessing a variable that has not yet been defined. By default, such errors are not displayed to the user at all - although, as you will see, you can change this default behaviour.

Warnings: These are more serious errors - for example, attempting to include() a file which does not exist. By default, these errors are displayed to the user, but they do not result in script termination.

Fatal errors: These are critical errors - for example, instantiating an object of a non-existent class, or calling a non-existent function. These errors cause the immediate termination of the script, and PHP’s default behaviour is to display them to the user when they take place.

- The process of combining data from different resources.

- The combined data is provided to the users with unified view.

- Information from different enterprise domains are integrated – known as Enterprise Information Integration.

- Useful for merging information from different technologies among enterprises.

- The sub areas of data integration are 

1. Data Warehousing.

2. Data Migration.

3. Master Data Management.

Internet Service Provider (ISP) is a company offering access to internet. They offer various services:

1. Internet Access

2. Domain name registration

3. Dial-up access

4. Leased line access

There exist several ways to connect to the internet. Following are these connection types available:

* Dial-up Connection

* ISDN

* DSL

* Cable TV Internet connections

* Satellite Internet connections

* Wireless Internet Connections

The Spring IoC is responsible for creating the objects,managing them (with dependency injection (DI)), wiring them together, configuring them, as also managing their complete lifecycle.