Database Indexing for Performance

Imagine searching for a specific topic in a massive textbook without an index. You'd flip through every page, right?

• Databases face a similar challenge when retrieving data.
• Without help, they might scan every single row to find what you need.
• This lesson explores database indexing: a powerful technique to dramatically speed up data retrieval.

A database index is like a book's index. It's a special lookup table that the database search engine can use to speed up data retrieval.

• It contains a sorted list of values from one or more columns.
• Each value points directly to the location of the full row of data.
• This allows the database to quickly jump to the relevant data, rather than scanning the entire table.