HCLTech QA Lead Interview Questions and Answers

A clustered index is a type of index that determines the physical order of data in a table.

• A table can have only one clustered index.

• It is created on the primary key column by default.

• It speeds up data retrieval operations.

• It is used for range searches and sorting.

• Example: Clustered index on a customer ID column in a sales table.

SELECT is used to retrieve data from a table, while SELECT INTO is used to create a new table with data from an existing table.

• SELECT retrieves data from a table and returns the result set.

• SELECT INTO creates a new table with the same columns and data types as the original table.

• SELECT INTO can also be used to create a temporary table.

• SELECT INTO can be used to create a backup copy of a table.

• SELECT INTO can be used to...read more

Data purging is the process of permanently deleting or removing data from a system or database.

• It is done to free up storage space and improve system performance.

• It involves identifying and removing outdated, redundant, or irrelevant data.

• It is important to ensure that sensitive or confidential data is securely deleted.

• Examples include deleting old user accounts, removing expired product listings, and clearing out old