SQL Interview Questions #13: Is the index fit for query?

SQL code copied to buffer

Task 13:

Is the following index a good fit for the query? 
| CREATE INDEX tbl_idx ON tbl (date_column);

| SELECT COUNT(*)
| FROM tbl
| WHERE EXTRACT(YEAR FROM date_column) = 2024;
Source: The 3-Minute SQL Indexing Quiz

Good fit: No need to change anything.

Bad fit: Changing the index or query could improve performance.

Mark all correct answers and click the "Check!" button

Support SQLtest.online

This project has only one funding source: your donations. The monthly maintenance cost is $100.

Last month I added a new MariaDB database with a preloaded University DB, 9 new questions, and refactored many questions and lessons.

With your support, I plan to continue this work: write new lessons and tasks, and improve existing lessons.

To keep the project running next month, we need to collect at least this amount by the end of this month. Anything above it goes to new lessons, exercises, and features.

Received: $29.58 Goal: $100.00

Progress: 30%

SQL in 10 Minutes a Day by Ben Forta

Whether you're an application developer, database administrator, web application designer, mobile app developer, or Microsoft Office users, a good working knowledge of SQL is an important part of interacting with databases. And Sams Teach Yourself SQL in 10 Minutes offers the straightforward, practical answers you need to help you do your job.

Login

Register