#composite-keys

5.10 Composite Keys

5.10 Composite Keys Problem You need to use multiple fields together as a single key in a hash table. Examples include (user_id, timestamp) , (x, y) coordinates, (source, destination) , or (name, version) . Treating each field separately leads to incorrect grouping or lookup. Treating them together requires a consistent definition of equality and hashing. Solution Define a composite key type with equality and hashing over all relevant fields. Key:...