Query Optimization

Postgres engineers detail how to make DELETE perform at scale

A technical blog post explains optimizations for using Postgres DELETE efficiently rather than resorting to table truncation or partition dropping. The authors applied tuning techniques—focused on cache and index performance—to a Postgres-backed durable workflows and queues system handling tens of thousands of workflows and steps per second, in order to enforce data retention policies.

dbos.dev · 2026-10-15

Engineering team cuts ClickHouse query latency from 85 seconds to sub-second

A team tasked with speeding up ClickHouse for its largest customers found a critical dashboard query taking over 85 seconds and scanning nearly 2 billion rows across 198GB of data. Over four months, they applied a series of incremental, non-flashy optimizations—tackling issues like the overhead of ReplacingMergeTree's FINAL clause on mutable event data and an inefficient partition key—to bring the query down to sub-second response times.

jordivillar.com · 2026-09-09