icexelloss commented on issue #34786: URL: https://github.com/apache/arrow/issues/34786#issuecomment-1494694461
> Another design issue to notice is that the output schema may (though not usually) differ between planning-time and execution-time. In particular, the output schema depends on the aggregates, which depend on their kernels, which depend on the function registry for function resolution as well as on the exec-context for kernel output-type resolution. Both the function registry and the exec-context, which contains it, may differ (or at least be incompatible for output-schema purposes) between planning-time and execution-time. In particular, at planning-time the current code can only assume a default exec-context. Looks like the best we could do is allow the exec-context to be passed in at planning-time, but this would require changing the signature of a large number of Arrow Substrait functions. Can you give an example of when does the output schema differs in "planning-time" vs "execution'time"? -- 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]
