alamb opened a new issue, #8227: URL: https://github.com/apache/arrow-datafusion/issues/8227
### Is your feature request related to a problem or challenge? We would like to use "statistics" in our project for transformations that rely on the statisics being "correct" (e.g. that the there are no values outside the `min` and `max` range). DataFusion has several optimizations like this too that rely on statistics being correct such as skipping file scans with limits such as in https://github.com/apache/arrow-datafusion/blob/e54894c39202815b14d9e7eae58f64d3a269c165/datafusion/core/src/datasource/statistics.rs#L34-L33. There are also suggestions of additional such optimizations like https://github.com/apache/arrow-datafusion/issues/6672 However the current Statistics code seems to make it hard to manage the 'are the statistics exact and can they be guaranteed for transformations' (@crepererum noted this quite some time ago on https://github.com/apache/arrow-datafusion/issues/5613). This has recently lead to several bugs such as * https://github.com/apache/arrow-datafusion/pull/8049 * https://github.com/apache/arrow-datafusion/pull/8094 We would like to make it clearer what is known and what is an estimate is know (e.g. the min/max of row counts may be known, but the actual value may be an estimate after a filter). This is described in more detail on https://github.com/apache/arrow-datafusion/issues/8078 As we began exploring this concept we ran into several issues with Statistics and I think it is getting big enough to warrant its own tracking epic Related items - [ ] https://github.com/apache/arrow-datafusion/issues/8078 - [ ] https://github.com/apache/arrow-datafusion/issues/8133 - [ ] https://github.com/apache/arrow-datafusion/issues/8099 - [ ] https://github.com/apache/arrow-datafusion/issues/7490 - [ ] https://github.com/apache/arrow-datafusion/issues/5614 - [ ] https://github.com/apache/arrow-datafusion/issues/5613 ### Describe the solution you'd like _No response_ ### Describe alternatives you've considered _No response_ ### Additional context This is somewhat related -- 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]
