One
| Input | Output | Alias | 
|---|---|---|
| ✔ | ✗ | 
Description
The One format is a special input format that doesn't read any data from file, and returns only one row with column of type UInt8, name dummy and value 0 (like the system.one table).
Can be used with virtual columns _file/_path  to list all files without reading actual data.
Example Usage
Example: