monotonically_increasing_id function
Applies to: 
Databricks SQL Databricks Runtime
Returns monotonically increasing 64-bit integers.
Syntax
monotonically_increasing_id()
Arguments
This function takes no arguments.
Returns
A BIGINT.
The generated ID is guaranteed to be monotonically increasing and unique, but not consecutive. The function is non-deterministic, so it may return different values if called multiple times for the same row.
Examples
SQL
> SELECT monotonically_increasing_id();
0