v.20.10New Feature
Add Ability to Remove Column Properties and Table TTLs in ClickHouse
Add the ability to remove column properties and table TTLs. Introduced queriesALTER TABLE MODIFY COLUMN col_name REMOVE what_to_removeandALTER TABLE REMOVE TTL. Both operations are lightweight and executed at the metadata level. #14742 (alesapin).
Why it matters
This feature addresses the need to cleanly remove unwanted column properties and table TTL definitions without heavy operations. It improves metadata management by enabling lightweight modifications that can simplify schema evolution and maintenance tasks.How to use it
Use the queryALTER TABLE MODIFY COLUMN col_name REMOVE what_to_remove to remove specific properties from a column. To remove the table-level TTL, execute ALTER TABLE REMOVE TTL. Both commands operate at the metadata level, making them efficient and fast.