Article Karthickraja S · Dec 18, 2025 2m read

The Power of Indexing in Database Tables

When working with databases, most developers understand the concept of an index and why it's used: to speed up data retrieval. But the real impact of indexing often becomes clear only when you compare scenarios with and without it.

Do you Know what Happens Without an Index?
Imagine a table with three columns: Name, Age, and MobileNumber.


Now, consider this query:

If the Age column does not have an index, the database engine will:

  • Check if the WHERE condition field has an index.
  • If not, it will scan the entire table (a full table scan).
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