❌ Only one array field per compound index (MongoDB limitation) ❌ Index size can explode if arrays are huge (each element → one index entry) ❌ Performance degrades with very high cardinality arrays (many unique values per document)
If you had a specific software or protocol in mind (e.g., “multikey in Redis” or “multikey in AWS KMS”), let me know and I’ll narrow the review. multikey
❌ Key management becomes complex – which slot holds which key? ❌ Some software assumes one key per token ❌ Limited storage (e.g., YubiKey 5 holds ≤ 25 resident FIDO2 keys) ❌ Only one array field per compound index