this is a normalized data table diagram.

+----------------+
|USERS BY EMAIL  |
+--+-----+-------+
|id|email|user_id|
+--+-----+-------+
| 1|b@o.b|      1|
| 2|c@r.l|      2|
+--+-----+-------+
  +---------------+
  |USERS          |
  +--+--------+---+
  |id|    name|age|
  +--+--------+---+
  | 1|     bob| 19|
  | 2| charlie| 23|
  +--+--------+---+