Part 136: Filtered & Partial Indexes

Why index 10,000,000 completed orders when you only ever query pending orders?

1. Syntax

-- Indexes only rows where status is 'pending' (saves 95% disk space!):
CREATE INDEX idx_pending_orders 
ON orders (created_at) 
WHERE status = 'pending';

Key Takeaways

• Partial indexes dramatically reduce index size and accelerate write speeds.

In Part 137, we learn Reading Execution Plans: EXPLAIN and EXPLAIN ANALYZE!