The effectiveTime (field) andfields in theenable and
fields in the enable the use of a "log style" append-only data model to track all changes to each
, providing full traceability. Once released, a row in any of these files will always remain unchanged. Historic data is supplied in
thedating the dating back to the first release
informat in format in 2002.
In order to change the properties of a current
(and, therefore, to create a new version of it), a new row is added to the applicable file, containing the updated fields, with
thefield the field set to true and the timestamp in the
effectiveTime (field) field indicating the nominal date on which the new version was released.
To inactivate aa a
a new row is added, containing the same data as the final valid version of
thebut with thefield the but with the field set to false and the timestamp in the
effectiveTime (field) field fi eld indicating the nominal date of the release in which the final version ceased being valid.
Where editorial policy does not allow a particular property of ato a
to be changed whilst keeping the
sametheas same the as a whole is inactivated (as described above), and a new row added with a new id, the
effectiveTime (field) set to the nominal date of the release in which this version of
thebecame the became valid, and
thefield the field set to true.
It is thus possible to see both the current values and any historical values of aat a
at any point in time.
Content will not be future dated with respect to the release that it appears in, although a release itself may be released a few days before its nominal release date. Where there is a business requirement for specifying a future activation date for somethis some
this may be modeled using
The following example demonstrates how the history mechanism works on the Concept file, but the same rules apply equally well to theandmember the
and member files. In this example,
theassociated the associated with the
moduleId (field) and
definitionStatusId (field) have been shown in place of their
SCTID (data type) values.
A new
(101291009) is
added ad ded on the 1st July 2007:
In the next release (on 1st January 2008), theis the
is moved from |Module 1| to |Module 2|. Because the moduleId field is not immutable,
themay the may be updated simply by adding a new record with the same Id.
In the next release (on 1st July 2008), theis changed from beingto beingthe
is changed from being to being Id | effectiveTime (field) | | moduleId (field) | definitionStatusId (field) |
|---|
101291009 | 20070701 | 1 | | Scg expression |
|---|
ShowParts | term | scg-expression| t | 900000000000074008|Primitive| |
|---|
|
|
101291009 | 20080101 | 1 | | Scg expression |
|---|
ShowParts | term | Scg expression |
|---|
ShowParts | id+term | | Concept |
|---|
| t | 900000000000074008|Primitive| |
|---|
|
|
101291009 | 20080701 | 1 | | Scg expression |
|---|
ShowParts | term | Scg expression |
|---|
ShowParts | id+term | | Concept |
|---|
| t | 900000000000073002|Defined| |
|---|
|
|
In the next release (on 1st January 2009), theis the
is deactivated:
Id | effectiveTime (field) | | moduleId (field) | definitionStatusId (field) |
|---|
101291009 | 20070701 | 1 | | Scg expression |
|---|
ShowParts | term scg-expression | ShowParts| id+term | | 900000000000074008|Primitive| |
|
|
101291009 | 20080101 | 1 | | Scg expression |
|---|
ShowParts | term | Scg expression |
|---|
ShowParts | id+term | | Concept |
|---|
| t | 900000000000074008|Primitive| |
|---|
|
|
101291009 | 20080701 | 1 | scg-expression ShowPartsterm | scg-expression | ShowParts| id+term | | 900000000000073002|Defined| |
|
|
101291009 | 20090101 | 0 | scg-expression ShowPartsterm | | Scg expression |
|---|
ShowParts | id+term | | Concept |
|---|
| t | 900000000000074008|Primitive| |
|---|
|
|
Notes
At no stage in this process are previously written records ever amended. Once a record has been released in ait a
it will continue to be released in exactly the same form in future Changes are only recorded at the point of release in theIf arecord the
If a record is changed a number of times between releases (during an edit and review process), only the most recently amended record will be appended to thenot the not individual records showing each separate edit to the released In the last example, as well as inactivating the concept (active=0), the definitionStatusId (field) is changed from
| Scg expression |
|---|
ShowParts | id+term| Concept |
|---|
| t | 900000000000073002|Defined| |
|---|
| ShowFormat | inline |
|---|
|
to | Scg expression |
|---|
ShowFormat | nospace| Concept |
|---|
| t | 900000000000074008|Primitive| |
|---|
|
. In practice this change is not essential since the value of data columns is ignored when ais a is inactive. Although the change is unnecessary and insignificant, it typically occurs since all the relationships of an inactive concept must also be inactive, and as a result, from the perspective of the authoring environment the concept cannot be regarded as | Scg expression |
|---|
ShowFormat | nospace| Concept |
|---|
| t | 900000000000073002|Defined| |
|---|
|
.
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