pub const KEY_MAX: usize = _; // 65_534usizeExpand description
The longest an index key may be, which is the longest name an element table takes.
A text value past this cannot be filed, and a write that would have to file one fails rather than storing a document the index will never find. A silent absence from an index is a query that returns the wrong answer with no way to tell, and that is worse than a write that says no.