HCLTech Interview Questions and Answers

Improving SQL performance involves optimizing queries, indexes, and server resources.

• Optimize queries by reducing complexity and avoiding unnecessary joins

• Use indexes to speed up data retrieval

• Ensure server resources are adequate for the workload

• Consider partitioning large tables to improve query performance

• Use stored procedures to reduce network traffic and improve security

Design view is used to create and modify database objects, while Datasheet view is used to view and edit data in tables.

• Design view allows users to create and modify tables, queries, forms, reports, and macros.

• Datasheet view displays data in a spreadsheet-like format and allows users to edit data directly.

• Design view is used to set properties and define relationships between tables.

• Datasheet view is used to sort, filter, and search for specific data.

• Design view is more suitab...read more

Index, trigger, and stored procedure are database objects used to improve performance and automate tasks.

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

• A trigger is a set of instructions that automatically executes in response to certain events, such as an insert, update, or delete operation on a table.

• A stored procedure is a precompiled set of SQL statements that can be called by other programs or scripts to perform a sp...read more

Joins are used to combine data from two or more tables in SQL. There are different types of joins.

• Inner join returns only the matching rows from both tables

• Left join returns all the rows from the left table and matching rows from the right table

• Right join returns all the rows from the right table and matching rows from the left table

• Full outer join returns all the rows from both tables

• Cross join returns the Cartesian product of both tables

Relationship in SQL refers to the association between two or more tables based on common fields.

• Relationships are established using foreign keys

• Types of relationships include one-to-one, one-to-many, and many-to-many

• Relationships can be visualized using ER diagrams

• Joins are used to retrieve data from related tables

Class module is a custom object in VBA that allows you to define your own properties and methods.

• Class modules are used to create custom objects in VBA

• They allow you to define your own properties and methods

• You can create instances of a class module and use them in your code

• Class modules are useful for encapsulating complex logic and data

• They can be used to create reusable code libraries