Databases Intermediate

What is Index?

A data structure that improves the speed of data retrieval operations on database tables at the cost of additional storage.

Indexes work like a book index — they allow the database to find rows without scanning the entire table. Without an index, a query on a million-row table checks every row. With an index, it jumps directly to matching rows.

Types include B-tree (default, good for ranges), hash (exact matches), GIN (full-text search), and GiST (geometric data). Over-indexing slows down writes since indexes must be updated on every INSERT/UPDATE.

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Related Terms

Connection String

A formatted string containing all parameters needed to establish a connection to a database server.

Prepared Statement

A pre-compiled SQL template that uses parameters instead of literal values, preventing SQL injection and improving performance.

A version-controlled change to a database schema that can be applied and reversed systematically.

Database Index Types

Different index structures (B-tree, Hash, GIN, GiST, BRIN) optimized for various query patterns and data types.

A centralized repository optimized for analytical queries that integrates data from multiple operational sources.

ORM (Object-Relational Mapping)

A technique that lets you interact with a database using object-oriented code instead of writing raw SQL queries.

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