zhouqingqing/qpmodel

we should realize the MarkJoin as HashJoin

9DemonFox opened this issue · 2 comments

9DemonFox commented
we should realize the MarkJoin as HashJoin
9DemonFox commented

When a markjoin deprived from IN clause, it can't be seen as a semi join, because there might be a "null".

9DemonFox commented

More precisely, EXIST, IN should use SEMI JOIN， but NOT IN is not SEMI JOIN. Understanding this , the work to simplefy markjoin can work on.