The Problem
While working on a production Laravel application, I encountered a critical performance issue: a report generation query was taking over 13 seconds to execute. This was impacting user experience and system performance significantly.
The query was complex, joining multiple tables with millions of records and performing aggregations across date ranges.
Initial Analysis
First, I used Laravel's query logging and EXPLAIN to understand what was happening:
EXPLAIN SELECT ...The results showed:
- Full table scans on multiple tables
- No proper indexing on join columns
- Missing composite indexes for WHERE clauses
- Inefficient subqueries
The Solution
1. Strategic Indexing
I created targeted indexes on frequently joined columns and WHERE clause conditions:
CREATE INDEX idx_user_date ON transactions(user_id, created_at);
CREATE INDEX idx_status_type ON orders(status, type);2. Query Refactoring
I broke down the complex query into optimized parts, eliminating unnecessary joins and using more efficient aggregation methods.
3. Database Structure Optimization
I reviewed and normalized the database schema, reducing redundant data and improving relationship definitions.
4. Caching Strategy
For frequently accessed reports, I implemented Redis caching with smart invalidation strategies.
Results
- Query time reduced from 13 seconds to 1 second
- Database load decreased by 85%
- User satisfaction significantly improved
- Cost savings on database infrastructure
Key Takeaways
- Always analyze query execution plans before optimization
- Strategic indexing is more important than adding many indexes
- Sometimes refactoring the query is better than adding indexes
- Caching should be part of the optimization strategy, not the only solution
Optimizing database queries requires a systematic approach and understanding of how databases work under the hood.