bharos opened a new issue, #15901: URL: https://github.com/apache/iceberg/issues/15901
### Feature Request / Improvement `StrictMetricsEvaluator.startsWith` currently [always returns `ROWS_MIGHT_NOT_MATCH`](https://github.com/apache/iceberg/blob/9a939d68358de9dac2c6ba9b236b675ebe477490/api/src/main/java/org/apache/iceberg/expressions/StrictMetricsEvaluator.java#L464-L466), ignoring file-level column bounds entirely. When the column's lower and upper bounds prove that every value in the file starts with the given prefix, the evaluator should return `ROWS_MUST_MATCH`. This allows the engine to skip unnecessary row-level filtering for `STARTS WITH` predicates, improving query performance on string-heavy workloads. Specifically, the evaluator can determine that all rows match `STARTS WITH <prefix>` when: - The column contains no null values - Both the lower and upper bounds start with the prefix (truncated lower/upper each equal the prefix) This mirrors how `eq` and the recently added `notStartsWith` (#15882) already use bounds in the same evaluator. ### Query engine None ### Willingness to contribute - [X] I can contribute this improvement/feature independently - [ ] I would be willing to contribute this improvement/feature with guidance from the Iceberg community - [ ] I cannot contribute this improvement/feature at this 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] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
