alamb opened a new issue, #10313: URL: https://github.com/apache/datafusion/issues/10313
### Is your feature request related to a problem or challenge? Many analytic systems store their data with some particular sort order, and the query engine can often take advantage of this sort order to both reduce memory usage and performance Specific examples in Datafusion include: 1. Emitting from [GroupBy](https://github.com/apache/datafusion/blob/main/datafusion/physical-plan/src/aggregates/order/partial.rs) early with partially sorted stream 2. [`SortMergeJoin`](https://github.com/apache/datafusion/blob/22311835bc1b4bd83b50e1c3875b0e725622b872/datafusion/physical-plan/src/joins/sort_merge_join.rs#L62-L86) 3. Sort removal via [`EnforceSorting`](https://docs.rs/datafusion/latest/datafusion/physical_optimizer/enforce_sorting/index.html) and [`replace_with_order_preserving_variants`](https://docs.rs/datafusion/latest/datafusion/physical_optimizer/replace_with_order_preserving_variants/index.html) This information is currently encoded in [`ExecutionPlan::maintains_input_order`](https://docs.rs/datafusion/latest/datafusion/physical_plan/trait.ExecutionPlan.html#method.maintains_input_order) [`ExecutionPlan::required_input_ordering`](https://docs.rs/datafusion/latest/datafusion/physical_plan/trait.ExecutionPlan.html#method.required_input_ordering) and [`PlanProperties`](https://docs.rs/datafusion/latest/datafusion/physical_plan/struct.PlanProperties.html) The same underlying analysis is often required for streaming (where determining what to emit is modeled as a sorted stream, for example on `date_trunc(ts)` of a stream sorted by timestamp). ### Describe the solution you'd like This epic has a list of optimizations / improvements that further take Here are some related issues: - [ ] https://github.com/apache/datafusion/issues/6672 - [ ] https://github.com/apache/datafusion/issues/7490 ### Describe alternatives you've considered _No response_ ### Additional context _No response_ -- 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: github-unsubscr...@datafusion.apache.org.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: github-unsubscr...@datafusion.apache.org For additional commands, e-mail: github-h...@datafusion.apache.org
