PostgreSQL Architecture

Understanding PostgreSQL's architecture is crucial for performance tuning: processes, memory structures (shared_buffers, work_mem), and storage.

Indexing Strategies

Index Type Use Case Performance Impact
B-tree General purpose, equality, range Excellent
Hash Simple equality only Very fast for equality
GIN Full-text, arrays, JSONB Good for composite values
GiST Geospatial, full-text Flexible, moderate speed
BRIN Large tables, correlated data Small size, efficient

Query Analysis Example

EXPLAIN (ANALYZE, BUFFERS) 
SELECT * FROM orders 
WHERE customer_id = 123 
  AND order_date >= '2024-01-01';

-- Create optimal index
CREATE INDEX idx_orders_customer_date 
ON orders(customer_id, order_date) 
WHERE order_date >= '2024-01-01';

Configuration Parameters

Key parameters: shared_buffers (15-25% of RAM), work_mem (for sorting), maintenance_work_mem (for VACUUM), effective_cache_size (70-80% of RAM).