Table TTL

https://clickhouse.com/docs/sql-reference/functions/date-time-functions

Precise TTL

TTL is relative to the exact datetime (e.g., 2025-06-05 15:42:30).

1 month - varying days

ALTER TABLE journal.otel_logs
MODIFY TTL toDateTime(Timestamp) + toIntervalMonth(1);

7 days

ALTER TABLE default.otel_logs
MODIFY TTL toDateTime(Timestamp) + toIntervalDay(7);

12 hours

ALTER TABLE journal.otel_logs
MODIFY TTL toDateTime(Timestamp) + toIntervalHour(12);

Aligned TTL

TTL is relative to the calendar date (e.g., 00:00, 12:00)

Start of month

ALTER TABLE journal.otel_logs
MODIFY TTL toStartOfMonth(Timestamp) + toIntervalMonth(1);

Start of day

ALTER TABLE journal.otel_logs
MODIFY TTL toStartOfDay(Timestamp) + toIntervalDay(1);

12:00

ALTER TABLE journal.otel_logs
MODIFY TTL toStartOfDay(Timestamp) + toIntervalHour(12);