DaZuiZui commented on PR #18006: URL: https://github.com/apache/iotdb/pull/18006#issuecomment-4901146022
Correction on the time column contract for FFT V1: we should support `TIMECOL` instead of requiring the input time column to be literally named `time`. Reason: the table model supports custom TIME column names, for example `CREATE TABLE t(event_time TIMESTAMP TIME, value DOUBLE FIELD)`. If FFT hard-codes `time`, valid table-model tables with a custom TIME column cannot use the built-in FFT directly, and this is also inconsistent with existing table/window TVFs that accept `TIMECOL`. The intended contract should be: - `TIMECOL` is optional and defaults to `time`, preserving the simple/default syntax. - `DATA` must include a TIMESTAMP/TIME column matching `TIMECOL`. - `ORDER BY` must contain exactly that selected time column in ascending order. - Numeric FFT value columns should exclude the selected time column and partition columns. So the previous wording in the PR description that says `ORDER BY time` should be corrected to `ORDER BY <TIMECOL>` / default `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]
