# `Arrow.Type.DictionaryEncoding`

Dictionary-encoding annotation on a `Arrow.Field`.

`id` is the dictionary's identifier within the IPC session — multiple
fields can share a single dictionary by referring to the same `id`.
`index_type` is the integer type used to index into the dictionary
from a record batch column. `is_ordered` indicates the dictionary
values are sorted in ascending order; some consumers rely on that.

This is *not* an `Arrow.Type` variant. The enclosing field's `type`
continues to describe the dictionary's *value* type. The
`DictionaryEncoding` lives on `Arrow.Field.dictionary`.

# `t`

```elixir
@type t() :: %Arrow.Type.DictionaryEncoding{
  id: non_neg_integer(),
  index_type: Arrow.Type.Int.t(),
  is_ordered: boolean()
}
```

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*Consult [api-reference.md](api-reference.md) for complete listing*