Indiabix Interview Questions and Answers

Q1. Define Network?

Ans: A network is a set of devices connected by physical media links. A network is recursively is a connection of two or more nodes by a physical link or two or more networks connected by one or more nodes.

Q2. What is RDBMS?

Ans: Relational Database Management Systems (RDBMS) are database management systems that maintain data records and indices in tables. Relationships may be created and maintained across and among the data and tables. In a relational database, relationships between data items are expressed by means of tables. Interdependencies among these tables are expressed by data values rather than by pointers. This allows for a high degree of data independence. An RDBMS has the capability to recombine the data items from different files, providing powerful tools for data usage.

Q3. What is PHP?

Ans: PHP is a server-side scripting language commonly used for web applications. PHP has many frameworks and cms for creating websites. Even a non-technical person can create sites using its CMS.WordPress,osCommerce are the famous CMS of PHP. It is also an object-oriented programming language like java, C-sharp etc. It is very easy for learning

Q4. What are the properties of the Relational tables?

Ans: Relational tables have six properties:

1. Values are atomic.
2. Column values are of the same kind.
3. Each row is unique.
4. The sequence of columns is insignificant.
5. The sequence of rows is insignificant.
6. Each column must have a unique name.

Q5. What is a Link?

Ans: At the lowest level, a network can consist of two or more computers directly connected by some physical medium such as coaxial cable or optical fibre. Such a physical medium is called as Link.

Q6. What is the use of "echo" in PHP?

Ans: It is used to print data in the webpage, Example: <?PHP echo 'Car insurance'; ?>, The following code print the text in the webpage

Q7. What is Normalization?

Ans: Database normalization is a data design and organization process applied to data structures based on rules that help to build relational databases. In relational database design, the process of organizing data to minimize redundancy is called normalization. Normalization usually involves dividing a database into two or more tables and defining relationships between the tables. The objective is to isolate data so that additions, deletions, and modifications of a field can be made in just one table and then propagated through the rest of the database via the defined relationships.

Q8. What is a node?

Ans: A network can consist of two or more computers directly connected by some physical medium such as coaxial cable or optical fibre. Such a physical medium is called Links and the computer it connects is called Nodes.

Q9. How to include a file to a php page?

Ans: We can include a file using "include() " or "require()" function with file path as its parameter.

Q10. What is De-normalization?

Ans: De-normalization is the process of attempting to optimize the performance of a database by adding redundant data. It is sometimes necessary because current DBMSs implement the relational model poorly. A true relational DBMS would allow for a fully normalized database at the logical level while providing physical storage of data that is tuned for high performance. De-normalization is a technique to move from higher to lower normal forms of database modelling in order to speed up database access.

Q11. What is a gateway or Router?

Ans: A node that is connected to two or more networks is commonly called a router or Gateway. It generally forwards the message from one network to another.

Q12. What's the difference between include and require?

Ans: If the file is not found by require(), it will cause a fatal error and halt the execution of the script. If the file is not found by include(), a warning will be issued, but execution will continue.

Q13. What are the different normalization forms?

Ans:

• 1NF: Eliminate Repeating Groups Make a separate table for each set of related attributes, and give each table a primary key. Each field contains at most one value from its attribute domain.
  
• 2NF: Eliminate Redundant Data If an attribute depends on only part of a multi-valued key, remove it to a separate table.
  
• 3NF: Eliminate Columns Not Dependent On Key If attributes do not contribute to a description of the key, remove them to a separate table. All attributes must be directly dependent on the primary key.
  
• BCNF: Boyce-Codd Normal Form If there are non-trivial dependencies between candidate key attributes, separate them out into distinct tables.
  
• 4NF: Isolate Independent Multiple Relationships No table may contain two or more 1:n or n:m relationships that are not directly related.
  
• 5NF: Isolate Semantically Related Multiple Relationships There may be practical constrains on information that justifies separating logically related many-to-many relationships.
  
• ONF: Optimal Normal Form A model limited to only simple (elemental) facts, as expressed in Object Role Model notation.
  
• DNF: Domain-Key Normal Form
  A model free from all modification anomalies is said to be in DNF.
  Remember, these normalization guidelines are cumulative. For a database to be in 3NF, it must first fulfil all the criteria of a 2NF and 1NF database.

Q14. What is the point-point link?

Ans: If the physical links are limited to a pair of nodes it is said to be the point-point link.

Q15. require_once(), require(), include().What is the difference between them?

Ans: require() includes and evaluates a specific file, while require_once() does that only if it has not been included before (on the same page). So, require_once() is recommended to use when you want to include a file where you have a lot of functions for example. This way you make sure you don't include the file more times and you will not get the "function re-declared" error.