mi_boolean mi_tab_unique(MI_AM_TABLE_DESC *tableDesc)
The access method can call this function from the am_create or am_insert purpose function. As the access method builds an index, it checks for unique key values if the mi_tab_unique() function returns MI_TRUE.
MI_TRUE indicates that the secondary access method must enforce unique keys for this index. MI_FALSE indicates that the secondary access method should not enforce unique keys for this index.