This is not necessarily true. It depends on your security model. You can use a bloom filter on each row. When the client does the encryption it encodes properti

This is not necessarily true. It depends on your security model. You can use a bloom filter on each row. When the client does the encryption it encodes properties about the encrypted value into a bloom filter. The filter’s construction can be scrambled according to the user (salted) using regular means (xor). An attacker would need to unsalt the filter and know how to query the filter in order to derive any useful information. Arbitrary querying of all users data is computationally impossible. The client can even do the salting and pass the salt to the server to support server-side querying, thus allowing a user to consent to a server to know information it otherwise wouldn’t know.