TTL docs don't mention that database name must be specified when using the `ON CLUSTER` clause

[raspreet-vunet]

Describe the issue In the article titled Manipulations with Table TTL, there is no mention of the fact that the database name is not optional (if the default database is not being used) when the ON CLUSTER clause is used.

Additional context An example of the problem described above

35432b02b254 :) select currentDatabase()

SELECT currentDatabase()

Query id: 343c7a10-d54b-4511-8ca5-c23387a9afe0

┌─currentDatabase()─┐
│ click             │
└───────────────────┘

1 row in set. Elapsed: 0.002 sec.

35432b02b254 :) create user if not exists foo on cluster mycluster

CREATE USER IF NOT EXISTS foo ON CLUSTER mycluster

Query id: 1553e588-3ddb-4f2e-a871-ce0d19f27391

┌─host─────────┬─port─┬─status─┬─error─┬─num_hosts_remaining─┬─num_hosts_active─┐
│ clickhouse-2 │ 9000 │      0 │       │                   3 │                0 │
│ clickhouse-3 │ 9000 │      0 │       │                   2 │                0 │
│ clickhouse-1 │ 9000 │      0 │       │                   1 │                0 │
│ clickhouse-4 │ 9000 │      0 │       │                   0 │                0 │
└──────────────┴──────┴────────┴───────┴─────────────────────┴──────────────────┘

4 rows in set. Elapsed: 0.061 sec.

35432b02b254 :) grant select on * on cluster mycluster to foo

GRANT ON CLUSTER mycluster SELECT ON * TO foo

Query id: 7283d1e8-4f6f-495d-8910-f7c32883154f

┌─host─────────┬─port─┬─status─┬─error─┬─num_hosts_remaining─┬─num_hosts_active─┐
│ clickhouse-4 │ 9000 │      0 │       │                   3 │                0 │
│ clickhouse-2 │ 9000 │      0 │       │                   2 │                0 │
│ clickhouse-3 │ 9000 │      0 │       │                   1 │                0 │
│ clickhouse-1 │ 9000 │      0 │       │                   0 │                0 │
└──────────────┴──────┴────────┴───────┴─────────────────────┴──────────────────┘

4 rows in set. Elapsed: 0.057 sec.

35432b02b254 :) show grants for foo

SHOW GRANTS FOR foo

Query id: e57e71a4-7fc2-48cd-b9bf-3ed9cbf716aa

┌─GRANTS FOR foo───────────────────┐
│ GRANT SELECT ON default.* TO foo │
└──────────────────────────────────┘

1 row in set. Elapsed: 0.001 sec.

Since I'm currently connected to the database click, I would expect that the grants are applied to all tables in the click database, instead of the default database

Here is the result of the same statements when I don't use the ON CLUSTER clause

35432b02b254 :) select currentDatabase()

SELECT currentDatabase()

Query id: d86be97b-5db5-40c5-955b-011372a2a9ea

┌─currentDatabase()─┐
│ click             │
└───────────────────┘

1 row in set. Elapsed: 0.001 sec.

35432b02b254 :) create user if not exists foo

CREATE USER IF NOT EXISTS foo

Query id: 4384cb16-fb35-4ebc-aa71-743cab983817

Ok.

0 rows in set. Elapsed: 0.002 sec.

35432b02b254 :) grant select on * to foo

GRANT SELECT ON * TO foo

Query id: 6efeed0f-14ef-4471-a32b-881ff174a2e0

Ok.

0 rows in set. Elapsed: 0.002 sec.

35432b02b254 :) show grants for foo

SHOW GRANTS FOR foo

Query id: 52f620e9-0f76-4d66-ae4f-e99c622d2058

┌─GRANTS FOR foo─────────────────┐
│ GRANT SELECT ON click.* TO foo │
└────────────────────────────────┘

1 row in set. Elapsed: 0.002 sec.