v.1.1.54337New Feature

Added Support for Aggregate Functions with Nullable Arguments

Official CH changelog text
Added support for aggregate functions of Nullable arguments even for cases when the function returns a non-Nullable result (added with the contribution of Silviu Caragea). Example: groupArray, groupUniqArray, topK.
Added support for aggregate functions that accept Nullable arguments, even when the result is non-Nullable, e.g., groupArray, groupUniqArray, topK.

Why it matters

This feature was created to allow aggregate functions to handle Nullable input arguments without losing the ability to return non-Nullable results. Previously, passing Nullable arguments to such functions could lead to errors or unsupported behavior. Now, users can process nullable data seamlessly inside aggregate functions, improving robustness and flexibility in data analysis.

How to use it

Use aggregate functions like groupArray, groupUniqArray, or topK directly with Nullable columns as their arguments. The functions will correctly handle Nullable inputs and return results according to their usual non-Nullable types. For example:

SELECT groupArray(nullable_column) FROM table

This will work without requiring explicit NULL handling or casting.
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