ClickHouse ® tips #6: Filtering data in subqueries to avoid joins

In ClickHouse, joining two tables and filtering by a column from the right-side table can be approached differently than in databases like Postgres, leading to significant performance improvements. Instead of performing a join when the result will always be filtered post-join, ClickHouse's columnar storage allows for direct filtering, which is highly efficient. By rewriting the query to utilize this feature, one can achieve faster results without creating a join table. Tinybird leverages ClickHouse to enable the creation of real-time API endpoints quickly, simplifying complex data operations, although it is currently in private beta and requires account creation for testing.

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