EXL Service Interview Questions, Process, and Tips

For Each Loop Container is used to iterate through a set of objects or files in SSIS packages.

• Used to perform repetitive tasks on a set of objects or files

• Can be used to loop through files in a directory or rows in a table

• Requires a data source and a variable to store the current object or file

• Can be configured to run in parallel or sequentially

SCD Type 2 is used to maintain historical data in a dimension table.

• SCD Type 2 is used to track changes in dimension attributes over time.

• It creates a new record for each change and maintains a history of all changes.

• It includes additional columns like start date, end date, and version number.

• Example: Employee table with changes in job title, salary, and department over time.

• It helps in analyzing trends and making info

Joins are used in SQL to combine data from two or more tables based on a related column.

• Joins are used to retrieve data from multiple tables.

• Common types of joins are inner join, left join, right join, and full outer join.

• Joins are performed using the JOIN keyword and specifying the tables to join and the columns to join on.

• Joins can be used to filter data based on a related column.

• Joins can also be used to combine dat

Difference between truncate, delete and drop

• Truncate removes all data from a table but keeps the structure

• Delete removes specific rows from a table

• Drop removes the entire table and its structure

• Truncate and drop cannot be rolled back, but delete can be

• Truncate is faster than delete as it does not log individual row deletions

Normalization is the process of organizing data in a database to reduce redundancy and improve data integrity.

• Normalization involves breaking down a table into smaller tables to reduce redundancy.

• It helps to avoid data inconsistencies and anomalies.

• Normalization is achieved through a series of normal forms, such as first normal form (1NF), second normal form (2NF), and so on.

• Each normal form has specific rules that mus...read more