Do Indexed Views Offer Faster Query Performance Than Simple Views?

Indexed Views vs. Simple Queries: A Performance Comparison

Introduction

The performance difference between using views and directly executing their underlying queries is often debated. This article clarifies this, highlighting the significant performance boost achievable with indexed views.

Performance Gains with Indexed Views

Unlike simple views, indexed views dramatically enhance query speed. They achieve this by creating a clustered index and storing pre-computed results persistently in the database. This pre-computation eliminates the need for expensive runtime calculations.

Optimization Techniques

Indexed views optimize queries in two key ways:

• Direct Querying: Queries can directly utilize the indexed view.
• Optimizer Integration: The query optimizer intelligently substitutes table references with the indexed view whenever it identifies this as the most efficient execution plan. This means performance improvements are possible even without explicit view referencing in the query.

Illustrative Example

Imagine a sales database with a preponderance of non-Lithuanian transactions. An indexed view focusing solely on Lithuanian sales data would significantly accelerate queries on this subset. The clustered index reduces the search space, for instance, from 21 to 7 records, leading to a notable performance improvement.

Summary

While simple views don't inherently improve query speed, indexed views offer substantial performance advantages through their inherent clustering and caching mechanisms. Their unique capabilities make them a powerful tool for database query optimization.

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