Could you explain what local keys are and how they are used in databases?

Local keys in databases are keys that are unique only within a specific table or data segment, not across the entire database. Typically, local keys are used to ensure the uniqueness of records within a table, such as a local primary key or a unique index.

Example: In the "Orders" table, there might be a local key "OrderID" that is unique only within this table but not necessarily unique in other tables.

Unlike global keys, which are unique across the entire database or even between databases, local keys are limited to their scope, which simplifies management and increases performance when working with data.