Clarification on Timestamp Precision in ADBC GetObjects Metadata

I have been looking at how parameterized types are represented in the schema returned by `AdbcConnectionGetObjects`. I found that for `DECIMAL(precision, scale)`, the precision and scale map to `xdbc_column_size` and `xdbc_decimal_digits` respectively. However, I wasn't able to determine where the time unit (`s`/`ms`/`us`/`ns`) of a `TIMESTAMP` type should be specified.

From my understanding, the column properties in `COLUMN_SCHEMA` are designed to mirror JDBC/ODBC metadata. However, I haven't found any standardized documentation that explicitly states how timestamp precision should be represented in this context.

My questions:

- Is there a standard way to represent timestamp precision in the ADBC metadata schema?
- If so, which field should hold this information?
- Does this align with JDBC/ODBC metadata standards, and if so, where is it documented?

Any clarification on this would be greatly appreciated! Thanks in advance.