Collection Functions in Hive

The following built-in collection functions in Apache Hive.

Size(Map<K.V>): Returns the number of elements in the map type.
Example:
SELECT mobile,places_lived,SIZE(mobile), SIZE(places_lived) FROM ExplodeTest2;



Size(Array<T>): Returns the number of elements in the array type.
Example:
SELECT SIZE(mobile), SIZE(places_lived) FROM ExplodeTest2;

map_keys(Map<K.V>)
It returns an unordered array containing the keys of the input map.

map_values(Map<K.V>)
It returns an unordered array containing the values of the input map.

Example:
SELECT stats,map_keys(stats) from explodetest3;
SELECT stats,map_keys(stats),map_values(stats) from explodetest3;

Array_Contains(Array<T>, value)
It returns TRUE if the array contains value.

Sort_Array:
Sorts the input array in ascending order according to the natural ordering of the array elements and returns it.

SELECT mobile, sort_array(mobile), places_lived, sort_array(places_lived) from ExplodeTest2;

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