A Redis hash is a field-addressable record under one key, not a schema-checked object or an automatically nested document. It is useful when callers need a few attributes without replacing the whole record. That advantage depends on access patterns, field sizes, and the meaning of replies, not merely on choosing the hash type. ...
UTF-8 encodes Unicode scalar values using one to four bytes. ASCII characters retain their familiar one-byte representation, while many other characters need longer sequences. This makes UTF-8 a useful interchange format, but it does not make arbitrary bytes valid text or every byte offset a character boundary. Correct handling requires an agreed encoding, strict validity rules where appropriate, and a clear distinction between bytes and decoded text. ...