clickhouse as a datasource

[talelk]

Hello,

It would be great to integrate clickhouse as a datasource for recommendation data.

[zhenghaoz]

It is a good idea. Do you have any interest to implement a interface for ClickHouse? Though I could implement it, there are more important things I need to do first (new features, bugs, etc.).

[talelk]

will try to look at this during the weekend. nice work by the way

[zhenghaoz]

Good. Since ClickHouse provides SQL similar to MySQL. ClickHouse interface can be derived from MySQL implementation:

1. Deploy a ClickHouse on local machine for unit tests.
2. Make a copy of MySQL implementation (storage/data/sql.go) as well as tests (storage/data/sql_test.go).
3. Rewrite SQLs for ClickHouse and make sure all tests pass.
4. Remember to register ClickHouse storage in storage/data/database.go.

[zhenghaoz]

Ｗe can define DSN for ClickHouse as clickhouse://localhost:9000. ClickHouse service has been added to test environment (#188).

[gyf19]

+1