It does allow you to query with SQL, but it's meant for OLAP workloads, not OLTP. Its internal architecture and storage is different to what you'd usually think of as a relational database, like Postgres. See https://clickhouse.com/docs/en/concepts/why-clickhouse-is-so...
The term "relational" is overloaded. Sometimes it means "you can use SQL" and sometimes it means "OLTP with data stored in an AoS btree".
(And sometimes, a pet peeve of mine, it means "data with relationships" which is based on misunderstanding the term "relation". If someone asks you if "your data is relational" they are suffering from this confusion.)
The term "relational" is overloaded. Sometimes it means "you can use SQL" and sometimes it means "OLTP with data stored in an AoS btree".
(And sometimes, a pet peeve of mine, it means "data with relationships" which is based on misunderstanding the term "relation". If someone asks you if "your data is relational" they are suffering from this confusion.)