Can you explain what is meant by global keys in a database?

Global keys in a database are unique identifiers that unambiguously define a record across the entire database or within a distributed system. Unlike local keys, which are only unique within a single table or segment, global keys ensure uniqueness throughout all parts of the system.

For example, in a distributed database or when using multiple tables, a global key can be a UUID or a composite key that guarantees no record will have the same key.

This is important for:

• Ensuring data integrity during scaling.
• Synchronizing and merging data from different sources.
• Simplifying links between tables and services.

Example: if you have multiple microservices with their own databases, a global key will allow you to unambiguously identify an object across all services.