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

from typing import Annotatedfrom moose_lib import OlapTable, OlapConfig, Key, ClickHouseTTLfrom pydantic import BaseModelfrom datetime import datetime class Event(BaseModel):    id: Key[str]    timestamp: datetime    email: Annotated[str, ClickHouseTTL("timestamp + INTERVAL 30 DAY")] events = OlapTable[Event](    "Events",    OlapConfig(        order_by_fields=["id", "timestamp"],        ttl="timestamp + INTERVAL 90 DAY DELETE",    ),)

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 .

Related

• See Modeling Tables for defining your schema
• See Applying Migrations to roll out TTL changes