kz930 opened a new issue, #8487: URL: https://github.com/apache/texera/issues/8487
### What happened? A port can finish having carried no rows. An upstream filter that matches nothing still ends its channel, and `DataProcessor` calls `on_finish` either way. `TableOperator` then builds its table out of no tuples, and since `Table.from_tuple_likes` reads the column names off the tuples it is given, the operator is handed a DataFrame with no columns at all rather than the declared columns with no rows under them. Every table operator that names one of its own columns raises `KeyError` on that column. Sort is the plainest case, but this reaches the visualization operators and any user-written `UDFTableOperator` as well. The expected behaviour is the one the schema already describes: the port's declared columns, empty. ### How to reproduce? Build a workflow of CSV File Scan, then Filter with a condition no row satisfies, then Sort on one of the scanned columns, and run it. Sort fails with `KeyError` naming the sort column, even though that column exists on the link. The same thing shows without the engine, from the Python worker's own models. `Table(Table.from_tuple_likes([]))` reports `columns: []`, and calling `sort_values(by=["x"])` on it raises `KeyError: 'x'`. Building the frame from the port's schema instead, through `pyarrow.Table.from_pylist([], schema=schema.as_arrow_schema()).to_pandas()`, gives columns `['x', 'name']` with dtypes `int32` and `object`, and the same sort succeeds with shape `(0, 2)`. ### Version/Branch 1.4.0-incubating-SNAPSHOT (main) ### Commit Hash (Optional) 1fbd34627 ### Relevant log output ```shell KeyError: 'x' ``` -- 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]
