| student615 2004-01-12, 11:54 am |
| quote:
Originally posted by mir92
Hi,
I'm a little confused about the conceptual model and implementation model, what's the diffrence between the two?
Conceptual model where you describe an employee table like
EMP_CODE PRIMARY KEY
EMP_NAME
EMP_DATEOFBIRTH
Implementation model you say
EMP_CODE NUMBER PRIMARY KEY,
EMP_NAME VARCHAR2(494) NOT NULL
..
..
..
So basically Conceptual model emphasis on capturing business data and implementation model takes care of datatype,constraints...etc
also
Conceptual model would have everything normalized, 3NF or higher. Implementation model may have denormalized tables because performance is better.
Hope this helps |