wangqiuhao0912 commented on pull request #7459: URL: https://github.com/apache/incubator-doris/pull/7459#issuecomment-1000392464
@morningman In fact, the meaning of this function is very simple, that is, to find the code1 corresponding to the smallest timestamp (ts) in this group, which will often be used in IoT data. For example, the two rows of data are as follows: equipment ts code1 equ_a 1640274843000 1.1 equ_a 1640274844000 2.5 Using udaf-iot-first(ts, code1) is 1.1, similar to first_value over(), but it is an aggregation within a group -- 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]
