JSONAnalyze aggregate function

[alexey-milovidov]

Use case
The aggregate function takes String argument with JSON and outputs Array with all distinct paths in JSON along with the smallest data type that can accomodate all data values.

Example:

{"a": 123, "b": "2020-01-01T01:02:03Z"}
{"c": [123, 456], "b": "2020-01-01T01:02:03Z", "d": {"a": -1}}

The function should return

[
('a', 'Nullable(UInt8)'),
('b', 'DateTime'),
('c', 'Array(UInt16)'),
('d.a', 'Nullable(Int8)')
]

[freedomDR]

Maybe I can achieve it ？

[alexey-milovidov]

@freedomDR This will be very helpful!

[alexey-milovidov]

The function should return the inferred type name, as the schema inference would do under the same settings.
Let's start with an ordinary function that will analyze just a single JSON.