,----------------.   
  |{{              |   
  |----------------|   
  |  card connector|   
  |  card plugins  |   
  |}               |   
  |}}              |   
  |                |   
  `----------------'   
           |           
           |           
,---------------------.
|{{                   |
|---------------------|
|card handler         |
|card parser          |
|card optimizer       |
|card buffer          |
|card cacher          |
|card "storage engine"|
|database database [  |
|database             |
|--                   |
|--                   |
|]                    |
|}                    |
|}}                   |
|                     |
`---------------------'