The key is used to create secondary indexes like HashIndex and BloomFilters.
The key is used to create secondary indexes like HashIndex and BloomFilters.
Useful for partially ordered keys.
For example if your key is
case class MyData(id: Int, name: Option[String]))
Suppose your key is MyData(1, "John") and your KeyOrder if on MyData.id then this indexableKey should return MyData(1, None) so you can search for keys like MyData(1, None) and get result MyData(1, "John").
This is called partial ordering and full reads on partial keys so you can store extra data with key without having to read the value.