====== Problem description ======

Two kinds of changes, which will require source adaptation, can be distinguished.

===== Changes in the structure =====
  * New column added.
  * Column was removed.
  * Column data type changed.
  * Column name changed.
  * New relation appeared.
  * Relation is removed.
  * Relation type changed.

===== Change of data =====
  * Records added.
  * Records removed.
  * Record altered.

Versioning should be kept in mind also. For example, we have “The Vocabulary” v.1 from 01.01.2012, and it has the records:

|**Procedure code	**|** Procedure name      ** |
|   А15	        | Complete blood count |
|   B17	        | X-ray photograph     |

Then we receive a new version of the “The Vocabulary” v.2 from 02.02.2012. It has the records:

|**Procedure code	**|** Procedure name      ** |
|   А15	        | Ultrasonography |
|   B17	        | X-ray photograph     |

Having the procedures account with structure:

|**Person_id	**|** Procedure code      ** |
|   P01	        | A15 |

We will encounter the invalid data after “The Vocabulary” v.2 will be applied.