joind columns from right table
1
1	2
1	2
1	3
1	2	3
join on expression
2
2	2
2	3
1
2
1	2	2	3
1	2	2	3	3
1	2	2	3
join on and chain
2	3
2	3
2	3	2	3
1
1	3
1	2	2	3
2	4
join on aliases
1	2	2	3
1	2	2	3
1	2	2	3
1	2	2	3
1	2	2	3
1	2	2	3
1	2	2	3
1	2	2	3
1	2	2	3
1	2	2	3
1	2	2	3
1	2	2	3
1	2	2	3
1	2	2	3
1	2	2	3
1	2	2	3
1	2	2	3
join on complex expression
2	3
2	3
2	3
2	3
2	3
duplicate column names
{"a1":1,"test.tab1_copy.a1":2}
{"a1":1,"test.tab1_copy.a1":2}
{"a1":1,"copy.a1":2}
{"a1":1,"copy.a1":2}
{"a1":1,"copy.a1":2}