Accenture ETL Tester Interview Questions and Answers

Q1. What is scd amd their types
Ans. 
SCD stands for Slowly Changing Dimensions, which manage historical data in data warehousing.
• SCD Type 0: Retain original data without tracking changes. Example: Static attributes like a product's SKU.

• SCD Type 1: Overwrite old data with new data. Example: Updating a customer's address without keeping the old one.

• SCD Type 2: Create a new record for each change, preserving history. Example: Tracking changes in a customer's...read more
Answered by AI
Add your answer
Q2. Rank function and its scenario
Ans. 
The RANK function assigns a unique rank to each row within a partition of a dataset based on specified criteria.
• RANK function is used in SQL to assign a rank to each row within a partition of a result set.

• It can handle ties by assigning the same rank to identical values, skipping subsequent ranks. For example, if two rows are tied for rank 1, the next rank will be 3.

• Commonly used in scenarios like ranking students base...read more
Answered by AI
Add your answer

Q1. Etl tools and technologies
Add your answer
Q2. Types of scd dimensions
Ans. 
Slowly Changing Dimensions (SCD) include Type 1, Type 2, and Type 3 dimensions.
• Type 1: Overwrite existing data with new data, no history is kept.

• Type 2: Create a new record for each change, maintaining history.

• Type 3: Create a new attribute to store changes, keeping limited history.
Answered by AI
View 1 more answer

Q1. Tools used for ETL testing
Ans. 
Some tools used for ETL testing include Informatica, Talend, SSIS, and Apache Nifi.
• Informatica

• Talend

• SSIS (SQL Server Integration Services)

• Apache Nifi
Answered by AI
Add your answer

Q1. Advanced SQL for large data handling
Ans. 
Advanced SQL techniques for handling large datasets
• Use indexing to improve query performance

• Optimize queries by avoiding unnecessary joins and subqueries

• Utilize partitioning and clustering to manage large tables efficiently

• Consider using window functions for complex analytical queries
Answered by AI
Add your answer

Multiple choice questions

Q1. What is the difference between union and union all?
Ans. 
Union combines and removes duplicates, while union all combines without removing duplicates.
• Union removes duplicates from the result set, while union all does not.

• Union is slower than union all because it has to perform an additional step to remove duplicates.

• Union all is used when duplicates are desired in the result set.

• Example: SELECT column1 FROM table1 UNION SELECT column1 FROM table2;

• Example: SELECT column1 FROM ...read more
Answered by AI
Add your answer
Q2. What is primary key?
Ans. 
Primary key is a unique identifier for each record in a database table.
• Primary key ensures each record in a table is unique

• It can be a single column or a combination of columns

• Primary key values cannot be NULL
Answered by AI
Add your answer