Time series functions as window functions

[rschu1ze]

The functions in https://clickhouse.com/docs/en/sql-reference/functions/time-series-functions take the timeseries as an (horizontal) array. This is awkward.

A standard column argument won't work either as the algorithms (e.g. period detection) need to see the entire input and query execution in ClickHouse is chunked.

What may work is to re-implement the functions as window functions.

Fiddle

@bhavnajindal

[UnamedRus]

need to see the entire input and query execution in ClickHouse is chunked.

Quite a bit of aggregate functions made in such way, that they consume whole input and keep it with little to no transformation.
Actual "compute" happens on finalization stage, where all data is finally visible in one "array".

For example windowFunnel and other sequence detection