joocer opened a new issue, #35389: URL: https://github.com/apache/arrow/issues/35389
### Describe the bug, including details regarding any error messages, version, and platform. Table.join has an attribute `coalesce_keys`, which the documentation says: > coalesce_keys[bool](https://docs.python.org/3/library/stdtypes.html#bltin-boolean-values), default [True](https://docs.python.org/3/library/constants.html#True) > If the duplicated keys should be omitted from one of the sides in the join result. In PyArrow v11, the columns used to perform the join were retained in the resultant table when this parameter was set to `False`. However, in v12, the column from the 'right' table (the one in the parameters) is omitted from the result. A review of the change log for v12 doesn't suggest this change in behaviour is intentional. This change in behaviour was observed in the matrix regression testing for [Opteryx](https://github.com/mabel-dev/opteryx), which has matrix regression testing across Mac, Linux and Windows, for Python versions 3.8, 3.9, 3.10 and 3.11, and for Left and Inner JOINs - all variations in the test matrix appear to have this same behaviour. No error is observed, only a change in behaviour. ### Component(s) Python -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
