On Wed, Apr 24, 2024 at 5:13 PM Richard Guo <guofengli...@gmail.com> wrote:
> In sort_inner_and_outer, we create mergejoin join paths by explicitly > sorting both relations on each possible ordering of the available > mergejoin clauses. However, if there are no available mergejoin > clauses, we can skip this process entirely. It seems that this is a > relatively common scenario. Checking the regression tests I noticed > that there are a lot of cases where we would arrive here with an empty > mergeclause_list. > FWIW, during the run of the core regression tests, I found that we enter sort_inner_and_outer with an empty mergeclause_list a total of 11064 times. Out of these occurrences, there are 293 instances where the join type is JOIN_UNIQUE_OUTER, indicating the need to create a UniquePath for the outer path. Similarly, there are also 293 instances where the join type is JOIN_UNIQUE_INNER, indicating the need to create a UniquePath for the inner path. Thanks Richard
