3.2.3. Relationship File Specification

The Relationship file holds one per row. Each is of a particular type, and has a source and a destination . An example of a is given below:

|Outpatient procedure| |Is a| |Procedure| where:

• |Outpatient procedure|

  is the source

  

  ;

• |Is a|

  is the

  

  

  ; and;

• |Procedure|

  is the destination

  

  .

  Table 11. Relationship file - Detailed Specification
  Field	Data type	Immutable	Purpose
  id	SCTID (data type)	Y	Uniquely identifies the .
  effectiveTime (field)	Time (data type)	N	Specifies the inclusive date at which the component version's state became the then current valid state of the component
  active (field)	Boolean (data type)	N	Specifies whether the 's state was or from the nominal release date specified by the effectiveTime (field) field.
  moduleId (field)	SCTID (data type)	N	Identifies the version's module. Set to a of 900000000000443000 |Module| within the metadata .
  sourceId (field)	SCTID (data type)	Y	Identifies the source of the version, i.e., the the version emanates from. Set to an of a in the file.
  destinationId (field)	SCTID (data type)	Y	Identifies the that is the destination of the version. Set to an of a in the file.
  relationshipGroup (field)	Integer	N	Groups together versions that are part of a logically associated relationshipGroup (field). All records with the same relationshipGroup (field) number and sourceId (field) are grouped in this way.
  typeId (field)	SCTID (data type)	Y	A enumeration value from the metadata that identifies the semantic type of the version. 116680003 |Is a| or a subtype of 410662002 |Concept model attribute| . For example |Is a| , or |associated morphology| .
  characteristicTypeId (field)	SCTID (data type)	N	A enumeration value that identifies the characteristic type of the version (i.e. whether the version is defining, qualifying, etc.) This field is set to a of 900000000000449001 |Characteristic type| in the metadata .
  modifierId (field)	SCTID (data type)	N	A enumeration value that identifies the type of (DL) restriction (some, all, etc.). Set to a of 900000000000450001 |Modifier| in the metadata .

  Only one

  

  record with the same id field will be current at any point in time. The current record will be the one with the most recent effectiveTimebefore or equal to the point in time under consideration.
  If the

  

  field of this record is false ('0'), then the

  

  is

  

  at that point in time. If the

  

  field is true ('1'), then there is a

  

  between the

  

  identified by sourceId (field) and destinationId (field) .
  The sourceId (field), destinationId (field), relationshipGroup (field), typeId (field), characteristicTypeIdand modifierId (field) will not change between two rows with the same id, in other words they are immutable. Where a change is required to one of these fields, then the current row will be de-activated (by appending a row with the same id and the

  

  field set to false) and a new row with a new id will be appended.
  The relationshipGroup (field) field is used to group

  

  with the same sourceId (field) field into one or more logical sets. A

  

  with a relationshipGroup (field) field value of '0' is considered not to be grouped. All

  

  with the same sourceId (field) and non-zero relationshipGroup (field) are considered to be logically grouped.
  The relationshipGroup (field) field will be an unsigned Integer (data type), and will not be limited to a single digit value. There is no guarantee that they will be assigned sequentially, and the values will not be unique across

  

  .
  The modifierId (field) field will initially be set to

  900000000000451002 |Some|

  to keep compatibility with the

  

  release. Widening the range of this field to include other values (such as |All|) will in future increase the expressive power of

  

  . However, this is likely to come at the cost of an increase in reasoning complexity, leading to potential issues for classification tooling.
  Notes:

1. The modiferId field has been included at this stage as the

   

   format is likely to be stable for at least a five year period, without addition or deletion of fields. Within that period it is anticipated that other modifierId (field) values will be added. Therefore, although not fully implemented at this stage, this field has been included in the initial RF2 specification as it represents an integral part of the

   

   used by

   

   .
2. Any expansion of

   

   to include

   

   with a modifierId (field) set to a value other than

   900000000000451002 |Some|

   will be discussed with

   

   first and approved by the Technical Committee.
3. Changes have been made to the "Immutability" values shown in the above table in the 2014-07-31 version. These changes reflect the fact that the values in the following columns of a uniquely identified relationship have occurred in historical data and in these cases tracking the history of these changes is of greater value that insisting on immutability.
   • relationshipGroup: The number can change though the logical content of the group represented should not change. Additionally no significance should be read into the relationshipGroup value of an inactive

     

     ;
   • characteristicType: This has changed in historical data but should not change in future;
   • modifierId: Since there is currently only one value for this no changes are possible but if the permitted values are extended as suggested above then it is likely that changes would be required.

Related Links

• 5.1.1 Defining Attributes by Hierarchy and Domain
• Chapter 6 - Individual Hierarchies

• 

• 3.1.3. Relationships
• 6. Unicode UTF-8 encoding

•