Are there any Hive array comparison functions/udf's

Question

Does hive have any array comparison functions/udf's to see if array=array?

For example:

Select a.xyz, b.abc from a left join b on a.C=b.D

Where C and D are arrays

Answer 1

Arrays are ordered structures,

 concat_ws( <separator> , <array> ) 

this function will join all the array elements into a string using the separator.

create table arrayDemo( id bigint, list array<String> );
create table dummy( a int );
insert into table dummy values ( 1 ) ; 
insert into arraydemo select 1, array("Paperino", "Topolino") from dummy;
insert into arraydemo select 2, array("Pippo", "Pluto") from dummy;
insert into arraydemo select 1, array("Pippo", "Pluto") from dummy; 

select * from arraydemo; 
+---------------+--------------------------+--+
| arraydemo.id  |      arraydemo.list      |
+---------------+--------------------------+--+
| 1             | ["Paperino","Topolino"]  |
| 2             | ["Pippo","Pluto"]        |
| 1             | ["Pippo","Pluto"]        |
+---------------+--------------------------+--+

select * 
     from arraydemo as a1 
          inner join arraydemo as a2 
          on concat_ws( "|", a1.list ) = concat_ws("|", a2.list ); 

+--------+--------------------------+--------+--------------------------+--+
| a1.id  |         a1.list          | a2.id  |         a2.list          |
+--------+--------------------------+--------+--------------------------+--+
| 1      | ["Paperino","Topolino"]  | 1      | ["Paperino","Topolino"]  |
| 2      | ["Pippo","Pluto"]        | 2      | ["Pippo","Pluto"]        |
| 1      | ["Pippo","Pluto"]        | 2      | ["Pippo","Pluto"]        |
| 2      | ["Pippo","Pluto"]        | 1      | ["Pippo","Pluto"]        |
| 1      | ["Pippo","Pluto"]        | 1      | ["Pippo","Pluto"]        |
+--------+--------------------------+--------+--------------------------+--+

I'm using it in this example in a "toString()" fashion. Sometimes the best is to compare only the important pieces of the arrays

 select * 
      from arraydemo as a1 
      inner join arraydemo as a2 
      on a1.list[0] = a2.list[0]; 

Hope this helps.