计数不同和不同计数KDB之间的差异

Question

KDB中"count distinct table"和"distinct count table"有什么区别？我以为count distinct table给了我不同行的数量但是不同的count表给了我不同的值

Answer 1

这种不同的行为在kdb + 2.7中被改变以阻止标量操作;

来自README.txt;

2011.10.12 - updated, see above entry
FIX

block scalar case for distinct (as it reverted to rand which was confusing)
 e.g. q)distinct 4
q.k - redefine rand:{*1?x} , system:."\\" and faster j10,j12