v.21.3Experimental Feature
Introduce Experimental Support for Window Functions in ClickHouse
Introduce experimental support for window functions, enabled with allow_experimental_window_functions = 1. This is a preliminary, alpha-quality implementation that is not suitable for production use and will change in backward-incompatible ways in future releases. Please see the documentation for the list of supported features. #20337 (Alexander Kuzmenkov).Why it matters
This feature aims to enable advanced analytical querying with window functions, allowing users to perform calculations across sets of table rows related to the current row without collapsing the result set. It addresses the need for more expressive SQL queries and advanced analytics directly in ClickHouse. Being an alpha-quality implementation, it is intended for testing and feedback, with future improvements and possible backward-incompatible changes expected.How to use it
To enable experimental window functions, set the server or session settingallow_experimental_window_functions = 1. This unlocks preliminary support for window functions. Users should refer to the documentation for current supported syntax and use cases.