alamb opened a new issue #1162: URL: https://github.com/apache/arrow-datafusion/issues/1162
**Is your feature request related to a problem or challenge? Please describe what you are trying to do.** Now that we have a nice ConstantPropagator and Simplifier framework, there are additional predicate rewrites we can do to improve query performance **Describe the solution you'd like** Implement additional algebraic simplification / rewrite rules to [constant_folding.rs](https://github.com/apache/arrow-datafusion/blob/master/datafusion/src/optimizer/constant_folding.rs) after https://github.com/apache/arrow-datafusion/pull/1153 has been merged Types of standard rewrites I think it would be good to have: ``` true OR <expr> --> true false OR <expr> --> expr true AND <expr> --> <expr> false AND <expr> --> false ``` There is also an interesting one in https://github.com/apache/arrow-datafusion/pull/1153 that would rotatate expr trees to isolate volatile functions: ``` (rand() + 1) + 2 --> rand() + (1 + 2) ``` The reason for doing that rewrite is that then the constant evaluator could convert to `rand() + 3` **Describe alternatives you've considered** There are various automated rewriting rules such as egg / tokomak (drafted in https://github.com/apache/arrow-datafusion/pull/1066 and https://github.com/apache/arrow-datafusion/pull/441 by @Dandandan and @pjmore ) which might be better / more powerful than implementing our own rules **Additional context** I am sure other query optimization systems have a good set of rewrite rules that we could investigate. I bet both postgres and spark have interesting optimizations to do. -- 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]
