Skip to main content

January 28, 2026 · 1 min read

Can you explain the time complexity of querying a database with an index versus without an index?

When querying a database with an index, the time complexity is generally O(log n) due to the use of binary search on the index structure. Without an index, the time…

debmedia

SOFTWARE_ARCHITECT // AI_ENGINEER

📅 Jan 28, 2026 ⏱ 1 min read

CY

Can you explain the time complexity of querying a database with an index versus without an index?

COVER // CAN YOU EXPLAIN THE TIME COMPLEXITY OF QUERYING A DATABASE WITH AN INDEX VERSUS WITHOUT AN INDEX?

When querying a database with an index, the time complexity is generally O(log n) due to the use of binary search on the index structure. Without an index, the time complexity is O(n) because the database must scan each row sequentially to find the desired data.

database indexing performance sql

Let's Talk

Have a Project in Mind?

Whether it's a software challenge, an AI integration, or a course enquiry — I'm always open to a real conversation.

hello@debasisbhattacharjee.com · +91 8777088548 · Mon–Fri, 9AM–6PM IST

Book a Free Strategy Call → Connect on LinkedIn Explore Courses