Add comment on encoding

src/main/java/uk/ac/ed/pguaglia/real/db/Database.java

@@ -196,8 +196,8 @@ public class Database {
 				break;
 			}
 		}
-		/* In all other cases, we simply execute the SQL expression
-		 * (corresponding to the given RA expression) in SQLite.
+		/* In all other cases, we directly execute the SQL query that
+		 * corresponds to the given RA expression.
 		 */
 		try {
 			var stmt = conn.createStatement();
@@ -222,6 +222,11 @@ public class Database {
 		}
 	}
 
+	/* We encode relation names as hexadecimal strings because identifiers
+	 * are case-insensitive in SQL while they are case-sensitive in REAL.
+	 * We also need a prefix in the name because identifiers in SQL cannot
+	 * start with a digit.
+	 */
 	public static String encode(String name) {
 		return PREFIX + HexFormat.of().formatHex(name.getBytes());
 	}