n1
1
2
NULL
count(distinct n1)
2
n2
11
12
13
NULL
count(distinct n2)
3
s
one
two
NULL
count(distinct s)
2
vs
eleven
twevle
thirteen
NULL
count(distinct vs)
3
t
eleven
twelve
foo
bar
NULL
count(distinct t)
4
n1	n2
1	11
2	11
2	12
2	13
NULL	13
2	NULL
count(distinct n1,n2)
4
n1	s
1	one
2	two
NULL	two
2	NULL
count(distinct n1,s)
2
s	n1	vs
one	1	eleven
two	2	eleven
two	2	twevle
two	2	thirteen
two	NULL	thirteen
NULL	2	thirteen
two	2	NULL
count(distinct s,n1,vs)
4
s	t
one	eleven
two	eleven
two	twelve
two	foo
two	bar
NULL	bar
two	NULL
count(distinct s,t)
5
count(distinct n1)	count(distinct n2)
2	3
count(distinct n2)	n1
1	NULL
1	1
3	2
count(distinct n)
5000
Variable_name	Value
Created_tmp_disk_tables	1
count(distinct s)
5000
Variable_name	Value
Created_tmp_disk_tables	1