v.24.8New Feature

Support Enhanced JOIN Strictness with Inequality Conditions

Support more variants of JOIN strictness (LEFT/RIGHT SEMI/ANTI/ANY JOIN) with inequality conditions which involve columns from both left and right table. e.g. t1.y < t2.y (see the setting allow_experimental_join_condition). #64281 (lgbo).
Support for additional JOIN strictness variants including LEFT/RIGHT SEMI/ANTI/ANY JOIN with inequality conditions involving columns from both joined tables.

Why it matters

This feature extends ClickHouse's JOIN capabilities by allowing inequality conditions (e.g., t1.y < t2.y) in semi and anti joins with more strictness types. It enables more flexible and expressive queries involving relationships between tables, which were previously unsupported or limited. This improves query expressiveness and analytical power for users dealing with complex join conditions.

How to use it

Enable the experimental feature by setting allow_experimental_join_condition to 1 in the server configuration or query settings. Then use the new JOIN strictness variants (LEFT/RIGHT SEMI/ANTI/ANY JOIN) with inequality conditions in your SQL queries as needed.