Vitkovice Interview Questions and Answers

Abstract class can have implementation while interface cannot. A class can implement multiple interfaces but only extend one abstract class.

• Abstract class can have constructors while interface cannot

• Abstract class can have non-abstract methods while interface cannot

• Interfaces are used for multiple inheritance while abstract classes are used for single inheritance

• Abstract classes can have instance variables while interfaces cannot

• Example: Abstract class - Animal, Interface - F...read more

Dataset is an in-memory representation of a database while DataReader is a forward-only, read-only stream of data.

• Dataset is disconnected and can be modified while DataReader is connected and read-only

• Dataset can hold multiple tables while DataReader can only hold one table at a time

• Dataset is slower than DataReader for large amounts of data

• Dataset can be used for data manipulation while DataReader is used for read-only access

Selenium is a tool for automating web browsers. WebDriver is a component of Selenium. Agile is a software development methodology.

• Selenium is used for automating web browsers to test web applications.

• WebDriver is a component of Selenium that provides a programming interface to control the browser.

• Agile is a software development methodology that emphasizes iterative development and collaboration between cross-functional teams.

• findElement() is used to locate a single web elemen...read more

An index is a data structure that improves the speed of data retrieval operations on a database table.

• Indexes are used to quickly locate data without having to search every row in a database table.

• Types of indexes include clustered, non-clustered, unique, and full-text indexes.

• Clustered indexes determine the physical order of data in a table, while non-clustered indexes create a separate structure to store the index data.

• Unique indexes ensure that each value in the index colu...read more

The Apache server configuration file is a text file that contains directives for configuring the Apache web server.

• The default location of the configuration file is /etc/httpd/conf/httpd.conf on Red Hat-based systems and /etc/apache2/apache2.conf on Debian-based systems.

• The configuration file is used to set options such as the server's port number, document root directory, and virtual hosts.

• The file can be edited manually or through a graphical interface such as Webmin or cPa...read more

PL/SQL is a procedural extension of SQL used for writing stored procedures, functions, and triggers.

• PL/SQL stands for Procedural Language/SQL, while SQL stands for Structured Query Language.

• SQL is used for querying and manipulating data in a database, while PL/SQL is used for writing procedural code like stored procedures and functions.

• PL/SQL allows for more complex logic and control flow compared to SQL.

• PL/SQL can include variables, loops, conditional statements, and excepti...read more

To extend LVM size, we need to add physical volumes and then extend the logical volume.

• Add a new physical volume using the 'pvcreate' command

• Extend the volume group using the 'vgextend' command

• Extend the logical volume using the 'lvextend' command

• Resize the file system using the appropriate command for the file system type