Overview
Query Optimization is the process of selecting the most efficient way to execute a SQL statement. Since SQL is a declarative language, there are often many ways to execute the same query, each with different performance characteristics.
Optimization Techniques
- Indexing: Using data structures to speed up lookups.
- Join Algorithms: Choosing between Nested Loop, Hash Join, or Merge Join.
- Cost-Based Optimization: Estimating the cost of different execution plans.
- Query Rewriting: Transforming the query into a more efficient form.