Manipulating SAMPLE BY expression
The following operations are available:
ALTER TABLE [db].name [ON CLUSTER cluster] MODIFY SAMPLE BY new_expression
The command changes the sampling key of the table to
new_expression (an expression or a tuple of expressions). The primary key must contain the new sample key.
ALTER TABLE [db].name [ON CLUSTER cluster] REMOVE SAMPLE BY
The command removes the sampling key of the table.
REMOVE are lightweight in the sense that they only change metadata or remove files.