fix(rust, python): projection_node always do projection locally if no…

[ritchie46]

…t pruned

fixes #5086

[alexander-beedie]

Barely had time to get home and eat dinner and there's already a patch! 🚀
Fantastic... :)

[ritchie46]

Barely had time to get home and eat dinner and there's already a patch! 🚀 Fantastic... :)

Yes.. I made the projection optimization better, but there are few edge cases coming in here and there. :(

[alexander-beedie]

Heh. It's always the optimisations that get you - even basic column pruning/pushdown has surprising edge-cases (especially in conjunction with joins). And I have to contend with multiple backends, with different rules for each... :)

I'm going to have a block of time coming up later in the month (significant other will be away for 2-3 weeks); should be able to make some progress on that parametric testing concept with chains of optimised/non-optimised operations 👍

[ritchie46]

Ah.. 2 weeks if man-cave can lead to great things. That will be the guard rails of future optimizations! :)