TTL (Time-to-Live) for ClickHouse Tables

Moose lets you declare ClickHouse TTL directly in your data model:

• Table-level TTL via the ttl option on OlapTable config
• Column-level TTL via ClickHouseTTL on individual fields

When to use TTL

• Automatically expire old rows to control storage cost
• Mask or drop sensitive columns earlier than the full row expiry

Configuration

import { OlapTable, ClickHouseEngines, Key, DateTime, ClickHouseTTL } from "@514labs/moose-lib"; interface Event {  id: Key<string>;  timestamp: DateTime;  email: string & ClickHouseTTL<"timestamp + INTERVAL 30 DAY">; // column TTL} export const Events = new OlapTable<Event>("Events", {  engine: ClickHouseEngines.MergeTree,  orderByFields: ["id", "timestamp"],  // Provide the ClickHouse TTL expression without the leading 'TTL'  ttl: "timestamp + INTERVAL 90 DAY DELETE", // table TTL});

Notes

• Expressions must be valid ClickHouse TTL expressions, but do not include the leading TTL keyword.
• Column TTLs are independent from the table TTL and can be used together.
• Moose will apply TTL changes via migrations using ALTER TABLE ... MODIFY TTL and MODIFY COLUMN ... TTL.

Related

• See Modeling Tables for defining your schema