Why is unique index not improving performance in this case? Furthermore, applying group attribute on cust column in table a surprising makes this 10x slower. Why?
n:1300000a:([]cust:n?`8; v1:n?100; v2:n?100; v3:n?100)/ with unique indexb1:`u#exec distinct cust from 100000#a\t select from a where cust in b122/ without unique indexb2:exec distinct cust from 100000#a\t select from a where cust in b222