An array type is a user-defined data type consisting of an ordered set of elements of a single data type.
An ordinary array type has a defined upper bound on the number of elements and uses the ordinal position as the array index.
An associative array type has no specific upper bound on the number of elements and each element has an associated index value. The data type of the index value can be an integer or a character string but is the same data type for the entire array.
An array type can be used as the type for global variables, SQL variables, and SQL parameters in SQL PL to provide flexible manipulation of a collection of values of a single data type.