`order by <sorted column> DESC limit N` queries are not optimised at segment level

A query like

SELECT *
FROM table
WHERE filter
ORDER BY sorted_col DESC
LIMIT 10;

is not optimised and hits the generic SelectionOrderByOperator.computePartiallyOrdered() which inserts up to 10k elements into a priority queue to discard all but the last 10. For ascending order, the query below is roughly 3-4x faster per segment.

SELECT *
FROM table
WHERE filter
ORDER BY sorted_col ASC
LIMIT 10;

[gortiz]

I think we need to invest some time optimizing sorted by, as there are too many cases where the optimizations can be applied but they are not. One example:

SELECT *
FROM table
WHERE filter
ORDER BY sorted_col ASC, any_other_thing
LIMIT 10;

Where any_other_thing may be a column, an operation or even a literal!

[Jackie-Jiang]

@ashishkf Good call! Created #9839 to track various improvements for AND operator