In one of the books about the general idea, _Translucent Databases_, the idea is to save the costs of securing the raw data. Someone might break into the database server (or listen on the wire) and find only encrypted values. This can make many different architectural use cases easier to deliver.
In the most extreme cases, the unencrypted values never leave the client. The database can concentrate on delivering storage and fast query answers without paying much attention to issues of security. Clients don't need to trust the database because they control the encryption.
In the most extreme cases, the unencrypted values never leave the client. The database can concentrate on delivering storage and fast query answers without paying much attention to issues of security. Clients don't need to trust the database because they control the encryption.