# UDA Dictionary Index

Following is the definition of the `mco_dict_index_info_t` structure that is used for UDA access as defined in `mcouda.h`:

index_no |
name | Index name in schema DDL definition.
flags | Bitmask describing this field (see values defined in the table below).
n_fields |
index |
n_keys_estimate |

The possible values for the bitmask flag are also defined in `mcouda.h`:

MCO_DICT_II_UNIQUE |
MCO_DICT_II_VOLUNTARY |
MCO_DICT_II_LIST |
MCO_DICT_II_AUTOID |
MCO_DICT_II_TREE |
MCO_DICT_II_HASH |
MCO_DICT_II_USERDEF |
MCO_DICT_II_KDTREE |
MCO_DICT_II_RTREE |
MCO_DICT_II_PATRICIA |
MCO_DICT_II_NULLABLE |
MCO_DICT_II_TRIGRAM |