ClickHouse materialized views provide a powerful way to restructure data in ClickHouse. We have discussed their capabilities many times in webinars, blog articles, and conference talks. One of the most common follow-on questions we receive is whether materialized views can support joins.
The answer is emphatically yes. This blog article shows how. If you are looking for a quick answer, here it is: materialized views trigger off the left-most table of the join. The materialized view will pull values from right-side tables in the join but will not trigger if those tables change.