Collection functions

Collections are useful for grouping heterogeneous information.

Collections can contain information of different data types, whereas arrays contain elements that must be of the same data type.

A collection consists of a sequence of name-value pairs. The names can be a maximum of 40 characters long. Values can be any built-in SQL type. You can reference the elements of the collection either by name or by their index starting from the first element, which has an index of 1. The collection is stored as a varchar field.

You can use the functions in this section to create collections and display their element types. You can also use any of the array functions in Array functions to retrieve and manipulate collection elements.