Cognizant Associate Tester Interview Questions and Answers

Drop command deletes the table structure along with data, while truncate command deletes only the data.

• Drop command removes the table structure and all its data, while truncate command only removes the data but keeps the table structure intact.

• Drop command is a DDL (Data Definition Language) command, while truncate command is a DML (Data Manipulation Language) command.

• Drop command is slower than truncate command as it ...read more

In my project, I perform validations such as data completeness, data accuracy, data transformation, and data integrity checks.

• Data completeness checks to ensure all required fields are populated

• Data accuracy checks to verify the correctness of data

• Data transformation checks to validate the transformation rules are applied correctly

• Data integrity checks to maintain data consistency and reliability

Star Schema is a type of database schema where a central fact table is connected to multiple dimension tables. Snowflake Schema is a normalized form of Star Schema where dimension tables are further normalized into sub-dimension tables.

• Star Schema has a central fact table connected to multiple dimension tables

• Snowflake Schema is a normalized form of Star Schema with sub-dimension tables

• Star Schema is denormalized for b...read more

Fact tables contain quantitative data while dimension tables contain descriptive attributes.

• Fact tables store measurable, quantitative data such as sales revenue or quantity sold

• Dimension tables store descriptive attributes related to the data in the fact table, such as product name or customer details

• Fact tables are typically normalized while dimension tables are denormalized for easier querying

• Example: In a sales dat...read more

HashMap is non-synchronized and allows null values, while Hashtable is synchronized and does not allow null values.

• HashMap is non-synchronized and not thread-safe, while Hashtable is synchronized and thread-safe.

• HashMap allows null values for both key and value, while Hashtable does not allow null keys or values.

• HashMap is faster than Hashtable as it is non-synchronized.

• HashMap is part of the Java Collections Framework

Types of exceptions in Selenium include NoSuchElementException, ElementNotVisibleException, StaleElementReferenceException, TimeoutException, and WebDriverException.

• NoSuchElementException: Thrown when an element could not be found in the DOM.

• ElementNotVisibleException: Thrown when an element is present in the DOM but not visible.

• StaleElementReferenceException: Thrown when an element is no longer attached to the DOM.

• Tim...read more

Abstract class can have both abstract and non-abstract methods, while interface can only have abstract methods.

• Abstract class can have constructors, fields, and non-abstract methods, while interface cannot.

• A class can implement multiple interfaces but can only inherit from one abstract class.

• Abstract classes are used to define a common behavior for subclasses, while interfaces are used to define a contract for classes ...read more

Project architecture refers to the overall structure of a software project, including components, modules, and their interactions.

• Project architecture defines how different components of a software project are organized and interact with each other.

• It includes the high-level design of the system, such as the database structure, data flow, and integration points.

• Project architecture also involves decisions on technologi...read more

Challenges in ETL testing include data quality issues, complex transformations, and handling large volumes of data.

• Data quality issues such as missing or incorrect data can impact testing results

• Complex transformations can be difficult to validate and may lead to errors in the ETL process

• Handling large volumes of data can slow down testing processes and require efficient testing strategies

Roles and responsibilities refer to the tasks and duties assigned to an individual within a specific job or position.

• Roles define the position or job title of an individual within an organization.

• Responsibilities outline the specific tasks, duties, and expectations associated with that role.

• Roles and responsibilities help clarify expectations, define boundaries, and ensure accountability.

• Examples include testing data e...read more

Use a dictionary to find duplicate values in an array of strings in Python.

• Create an empty dictionary to store the count of each string in the array.

• Iterate through the array and for each string, check if it exists in the dictionary. If it does, increment the count. If not, add it to the dictionary with a count of 1.

• After iterating through the array, check the dictionary for any strings with a count greater than 1. The

A deferred bug is a bug that is not fixed immediately but is scheduled to be fixed in a future release.

• Deferred bugs are usually lower priority bugs that do not impact the core functionality of the system.

• These bugs are documented and tracked for resolution in a later release.

• Examples of deferred bugs include cosmetic issues, minor usability problems, or non-critical functionality issues.

Use SQL query with ORDER BY and LIMIT to get 4th highest row based on a column

• Use ORDER BY clause to sort the column in descending order

• Use LIMIT 1 OFFSET 3 to get the 4th highest row

• Example: SELECT * FROM table_name ORDER BY column_name DESC LIMIT 1 OFFSET 3

Find min and max number in an array of strings

• Convert array elements to integers for comparison

• Use built-in functions like Math.min() and Math.max()

• Handle edge cases like empty array or non-numeric elements