Preserve: specifies enough time for which data is retained. Enter a value involving one and 365000. The default benefit is 3650. The worth in the Retain parameter should be increased than or equivalent to the worth of your DURATION parameter. TDengine instantly deletes facts that's older than the value on https://tdenginedatabase02219.answerblogs.com/20211637/top-latest-five-tdengine-database-urban-news