As I understand, there’s no relationships between tables in clikhouse.
So how I need to check data to be sure that querys with join will works right?
Here by tables:

CREATE TABLE db.categories
(
    category_id     UInt16 not null,
    category_name   String,
    primary key (category_id)
)
ENGINE = MergeTree;


CREATE TABLE db.services
(
    service_id  UInt16 not null,
    category_id UInt16 not null,
    primary key (service_id)
)
ENGINE = MergeTree;