Vol. I · A Postgres Handbook

The Query & the Schema

A reading-room reference for writing PostgreSQL by hand — selects to window functions, with the schema in plain view.

AdvancedPerformance & Indexes

HikariCP Tuning for PostgreSQL: Config #21

The query

SQL
-- Q: What is the optimal connection pool size for PostgreSQL? (Scenario 21)
-- A: Formula: connections = ((core_count * 2) + effective_spindle_count).
spring.datasource.hikari.maximum-pool-size: 15
spring.datasource.hikari.minimum-idle: 5
Tested against PostgreSQL 16

Note

“PostgreSQL uses a process per connection. Too many connections will exhaust memory. HikariCP is Spring Boot's default.