james-willis commented on issue #27155: URL: https://github.com/apache/datafusion/issues/27155#issuecomment-6777558121
copying a comment I left on #27143: > I wish this just wouldn't plan but I didn't make the change in this or my prior PR (https://github.com/apache/datafusion/pull/27143) because of some unpleasant implications. > In my prior planning PR we made mismatched "ARROW:extension:name" an error but the pair of a present and a null one goes to the present value. >IMO this should be a planning error because ARROW:extension:name really defines the type and types should match between branches but it leads to some unpleasant situations especially around literals, for example COALESCE(json_col, '{}') would fail. > This pain is just kind of a side effect of ARROW:extension:name being an insufficient type system. Here its limitation is that it cant describe what kinds of up/down casts are allowed. -- 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] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
