2010YOUY01 commented on issue #18319: URL: https://github.com/apache/datafusion/issues/18319#issuecomment-3794189969
> > [@sdf-jkl](https://github.com/sdf-jkl) that sounds great. IMO, preimage sounds misleading for something that's using interval containment to simplify a predicate, but maybe there will be other types of functions that can be reversed. > > The preimage terminology is from ClickHouse and I believe it refers to https://en.wikipedia.org/wiki/Image_(mathematics)#Inverse_image . > > If you have a better suggestion on terminology perhaps we can change it before we release 53.0.0 I think this is terminology bloat: we’re introducing a new term to describe an already well-known concept, and this might cause confusions. Fundamentally, this is just expression simplification. The difference is that traditional expression-simplification routines aim to reduce computation cost, while in the “preimage” case the simplification is done to enable predicate pruning. Here, we can tolerate slightly slower evaluation if it makes pruning possible. (and this issue's simplification case both made compute fast, and pruning possible) Perhaps we should simply call it `simplify_expr()` or `simplify_expr_for_pruning()`, and mention that this is equivalent to what ClickHouse calls a “preimage.” -- 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]
