minni31 commented on PR #12631: URL: https://github.com/apache/gluten/pull/12631#issuecomment-5277690403
**Note on the default value (`spark.gluten.sql.columnar.localTableScan`)** For this PR the config defaults to `false`. There is one known limitation: when an offloaded local scan feeds an operator that falls back to **vanilla row execution under the write path**, the inserted columnar-to-row transition is not yet codegen-safe. `VeloxColumnarToRowExec` does not implement `CodegenSupport`, so `FileFormatWriter`'s whole-stage codegen can cast it to `CodegenSupport` and fail with a `ClassCastException` (reproducible on Spark 3.3 via `INSERT ... VALUES` whose casts fall back through an `AnsiCast`). The feature itself is complete and fully covered by tests (which enable the config explicitly). This limitation will be addressed in a **follow-up PR** that makes the transition codegen-safe — reverting a no-op offload that is immediately topped by a columnar-to-row transition back to a vanilla `LocalTableScanExec` — after which the default will be **flipped to `true`**. Keeping the default off here lets this PR land safely while the codegen-safe handling is reviewed separately. -- 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]
