Question from the Infrastructure Architecture test

Your application is a directory of addresses saved in a single database table / document. Each entry contains:

• A name, address (number and street name) and a postal code

• The name of the entry creator (unique).

All users of your application can access all addresses in the database.
Users can only request all entries with a certain postal code.

You are asked to partition this table.

That means

• Replicating the table on multiple slave servers to distribute queries

• Splitting the table into multiple sub-tables, with each entry appearing in only one table

What are the possible partitioning keys to ensure that each query only reaches one table: