Day 28 of 100 Days of ClickHouse® – Understanding TTL (Time To Live) for Automated Data Lifecycle Management

Introduction

As data grows over time, storing every row forever becomes increasingly expensive and often unnecessary. Application logs, IoT events, monitoring metrics, audit records, and clickstream data typically have different retention requirements depending on their age.

ClickHouse® provides TTL (Time To Live), a powerful built-in feature that automates data lifecycle management. Instead of relying on scheduled cleanup scripts or manual DELETE operations, TTL rules can be defined directly within a table schema.

With TTL, ClickHouse can automatically:

Delete expired data