Indizes (EN)

Architecture

Indexes are a central concept in databases that can significantly improve query performance. The following illustration shows how indexes accelerate data access:

flowchart TD   A[SQL Query] --> B{Index exists?}   B -->|Yes| C[Index Scan]   B -->|No| D[Full Table Scan]   C --> E[Fast access to records]   D --> F[Slow sequential scan]   E --> G[Return result]   F --> G 

In Context

• Typically used together with primary keys, foreign keys, and frequently queried columns
• Related to: Database optimization, Query Performance, B-Trees, Hash Indexes
• Example use case: Searching for customers in a large table by last name