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Wiki source code of 8 Hierarchy

Version 15.1 by Helena K. on 2026/06/04 21:51
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1 {{box title="**Contents**"}}
2 {{toc/}}
3 {{/box}}
4
5 == 8.1 Scope ==
6
7 The [[Codelist>>doc:sdmx:Glossary 2\.1.Code list.WebHome]] described in the section on structural definitions supports a simple [[hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] of [[Codes>>doc:sdmx:Glossary 2\.1.Code.WebHome]] and restricts any child [[Code>>doc:sdmx:Glossary 2\.1.Code.WebHome]] to having just one parent [[Code>>doc:sdmx:Glossary 2\.1.Code.WebHome]]. Whilst this structure is useful for supporting the needs of the DataStructureDefinition and the MetadataStructureDefinition, it may not be sufficient for supporting the more complex associations between [[codes>>doc:sdmx:Glossary 2\.1.Code.WebHome]] that are often found in coding schemes such as a [[classification>>doc:sdmx:Glossary 2\.1.Statistical Classification.WebHome]] scheme. Often, the [[Codelist>>doc:sdmx:Glossary 2\.1.Code list.WebHome]] used in a DataStructureDefinition is derived from a more complex coding scheme. Access to such a coding scheme can aid applications, such as OLAP applications or data visualisation systems, to give more views of the data than would be possible with the simple [[Codelist>>doc:sdmx:Glossary 2\.1.Code list.WebHome]] used in the DataStructureDefinition. A [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] may be linked to an IndentifiableArtefact, in order to assist.
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9 Note that a [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] is not necessarily a balanced tree. A balanced tree is where
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11 (% style="color:#e74c3c" %)levels(%%) are pre-defined and fixed, (i.e. a (% style="color:#e74c3c" %)level(%%) always has the same set of [[codes>>doc:sdmx:Glossary 2\.1.Code.WebHome]], and any [[code>>doc:sdmx:Glossary 2\.1.Code.WebHome]] has a fixed parent and child relationship to other [[codes>>doc:sdmx:Glossary 2\.1.Code.WebHome]]). A [[statistical classification>>doc:sdmx:Glossary 2\.1.Statistical Classification.WebHome]] is an example of a balanced tree, and the support for a balanced [[hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] is a subset, and special case, of [[hierarchies>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]].
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13 The principal features of the [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] are:
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15 1. A child [[code>>doc:sdmx:Glossary 2\.1.Code.WebHome]] can have more than one parent.
16 1. There can be more than one [[code>>doc:sdmx:Glossary 2\.1.Code.WebHome]] that has no parent (i.e. more than one “root node”).
17 1. The (% style="color:#e74c3c" %)levels(%%) in a [[hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] can be explicitly defined or they can be implicit: i.e. they exist only as parent/child relationships in the coding structure.
18 1. [[Hierarchies>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] may be associated to the structures they refer to, via the HierarchyAssociation.
19
20 == 8.2 Inheritance ==
21
22 === 8.2.1 Class Diagram ===
23
24 [[image:image61.png]]
25
26 **Figure 35: Inheritance class diagram for the Hierarchy**
27
28 === 8.2.2 Explanation of the Diagram ===
29
30 ==== 8.2.2.1 Narrative ====
31
32 The [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] and //HierarchyAssociation// inherit from //MaintainableArtefact// and thus have identification, naming, versioning and a [[maintenance agency>>doc:sdmx:Glossary 2\.1.Maintenance agency.WebHome]]. The (% style="color:#e74c3c" %)Level(%%) is a //NameableArtefact// and therefore has an Id, multi-lingual name and multi-lingual description. A //HierachicalCode// is an //IdentifiableArtefact//.
33
34 It is important to understand that the [[Codes>>doc:sdmx:Glossary 2\.1.Code.WebHome]] participating in a [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] are not themselves contained in the list – they are referenced from the list and are maintained in one or more [[Codelists>>doc:sdmx:Glossary 2\.1.Code list.WebHome]]. This is explained in the narrative of the relationship class diagram below.
35
36 ==== 8.2.2.2 Definitions ====
37
38 The definitions of the various classes, [[attributes>>doc:sdmx:Glossary 2\.1.Attribute.WebHome]], and associations are shown in the relationship section below.
39
40 == 8.3 Relationship ==
41
42 === 8.3.1 Class Diagram ===
43
44 [[image:image62.png]]
45
46 **Figure 36: Relationship class diagram of the Hierarchy**
47
48 === 8.3.2 Explanation of the Diagram ===
49
50 ==== 8.3.2.1 Narrative ====
51
52 The basic principles of the [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] are:
53
54 1. The [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] is a specification of the structure of the [[Codes>>doc:sdmx:Glossary 2\.1.Code.WebHome]].
55 1. The [[Codes>>doc:sdmx:Glossary 2\.1.Code.WebHome]] in the [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] are not themselves a part of the [[artefact>>doc:sdmx:Glossary 2\.1.Artefact.WebHome]], rather they are references to [[Codes>>doc:sdmx:Glossary 2\.1.Code.WebHome]] in one or more external [[Codelists>>doc:sdmx:Glossary 2\.1.Code list.WebHome]].
56 1. The [[hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] of [[Codes>>doc:sdmx:Glossary 2\.1.Code.WebHome]] is specified in HierarchicalCode. This references the [[Code>>doc:sdmx:Glossary 2\.1.Code.WebHome]] and its immediate child HierarchicalCodes.
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58 A [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] can have formal (% style="color:#e74c3c" %)levels(%%) (hasFormalLevels="true"). However, even if hasFormalLevels="false" the [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] can still have one or more (% style="color:#e74c3c" %)Levels(%%) associated in order to document information about the HierarchicalCodes.
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60 If hasFormalLevels="false" the [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] is “value based” comprising a [[hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] of [[codes>>doc:sdmx:Glossary 2\.1.Code.WebHome]] with no formal (% style="color:#e74c3c" %)Levels(%%). If hasFormalLevels="true" then the [[hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] is “(% style="color:#e74c3c" %)level(%%) based” where each (% style="color:#e74c3c" %)Level(%%) is a formal (% style="color:#e74c3c" %)Level(%%) in the [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]], such as those present in [[statistical classifications>>doc:sdmx:Glossary 2\.1.Statistical Classification.WebHome]]. In a “(% style="color:#e74c3c" %)level(%%) based” [[hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] each HierarchicalCode is linked to the (% style="color:#e74c3c" %)Level(%%) in which it resides. It is expected that all HierarchicalCodes at the same hierarchic (% style="color:#e74c3c" %)level(%%) defined by the +parent/+child association will be linked to the same (% style="color:#e74c3c" %)Level(%%). Note that the +(% style="color:#e74c3c" %)level(%%) association need only be specified if the HierarchicalCode is at a different hierarchical (% style="color:#e74c3c" %)level(%%) (implied by the HierarchicalCode parent/child association) than the actual (% style="color:#e74c3c" %)Level(%%) in the (% style="color:#e74c3c" %)level(%%) [[hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] (implied by the (% style="color:#e74c3c" %)Level(%%) parent/child association).
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62 [Note that organisations wishing to be compliant with accepted models for [[statistical classifications>>doc:sdmx:Glossary 2\.1.Statistical Classification.WebHome]] should ensure that the Id is the number associated with the (% style="color:#e74c3c" %)Level(%%), where (% style="color:#e74c3c" %)Levels(%%) are numbered consecutively starting with (% style="color:#e74c3c" %)level(%%) 1 at the highest (% style="color:#e74c3c" %)Level(%%)].
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64 The (% style="color:#e74c3c" %)Level(%%) may have CodingFormat information defined (e.g. coding type at that (% style="color:#e74c3c" %)level(%%)).
65
66 A HierarchyAssociation links an IdentifiableArtefact (+linkedObject), that needs a [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]], with the latter (+linkedHierarchy). The association is performed in a certain context (+contextObject), e.g. a [[Dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] in the context of a [[Dataflow>>doc:sdmx:Glossary 2\.1.Dataflow.WebHome]].
67
68 ==== 8.3.2.2 ====
69
70 ==== Definitions ====
71
72 (% style="width:901.835px" %)
73 |**Class**|**Feature**|(% style="width:564px" %)**Description**
74 |[[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]]|(((
75 Inherits from:
76 //MaintainableArtefact//
77 )))|(% style="width:564px" %)A [[classification>>doc:sdmx:Glossary 2\.1.Statistical Classification.WebHome]] structure arranged in (% style="color:#e74c3c" %)levels(%%) of detail from the broadest to the most detailed (% style="color:#e74c3c" %)level(%%).
78 | |hasFormalLevels|(% style="width:564px" %)(((
79 If “true”, this indicates a [[hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] where the structure is arranged in (% style="color:#e74c3c" %)levels(%%) of detail from the broadest to the most detailed (% style="color:#e74c3c" %)level(%%).
80
81 If “false”, this indicates a [[hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] structure where the items in the [[hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] have no formal (% style="color:#e74c3c" %)level(%%) structure.
82 )))
83 | |+[[codes>>doc:sdmx:Glossary 2\.1.Code.WebHome]]|(% style="width:564px" %)Association to the top-(% style="color:#e74c3c" %)level(%%) [[Hierarchical Codes>>doc:sdmx:Glossary 2\.1.Hierarchical code.WebHome]] in the [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]].
84 | |+(% style="color:#e74c3c" %)level|(% style="width:564px" %)Association to the top (% style="color:#e74c3c" %)Level(%%) in the [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]].
85 |(%%)(% style="color:#e74c3c" %)Level|(((
86 Inherits from
87 //NameableArtefact//
88 )))|(% style="width:564px" %)(((
89 In a “(% style="color:#e74c3c" %)level(%%) based” [[hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] this describes a group of [[Codes>>doc:sdmx:Glossary 2\.1.Code.WebHome]] which are characterised by homogeneous coding, and where the parent of each [[Code>>doc:sdmx:Glossary 2\.1.Code.WebHome]] in the group is at the same higher (% style="color:#e74c3c" %)level(%%) of the [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]].
90 In a “value based’ [[hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] this describes information about the [[Hierarchical Codes>>doc:sdmx:Glossary 2\.1.Hierarchical code.WebHome]] at the specified nesting (% style="color:#e74c3c" %)level(%%).
91 )))
92 | |+codeFormat|(% style="width:564px" %)Association to the [[Coding Format>>doc:sdmx:Glossary 2\.1.Coding format.WebHome]].
93 | |+child|(% style="width:564px" %)Association to a child (% style="color:#e74c3c" %)Level(%%) of (% style="color:#e74c3c" %)Level(%%).
94 |CodingFormat| |(% style="width:564px" %)Specifies format information for the [[codes>>doc:sdmx:Glossary 2\.1.Code.WebHome]] at this (% style="color:#e74c3c" %)level(%%) in the [[hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] such as whether the [[codes>>doc:sdmx:Glossary 2\.1.Code.WebHome]] at the (% style="color:#e74c3c" %)level(%%) are alphabetic, numeric or alphanumeric and the [[code>>doc:sdmx:Glossary 2\.1.Code.WebHome]] length.
95 |HierarchicalCode| |(% style="width:564px" %)A hierarchic structure of [[code>>doc:sdmx:Glossary 2\.1.Code.WebHome]] references.
96 | |validFrom|(% style="width:564px" %)Date from which the construct is valid
97 | |validTo|(% style="width:564px" %)Date from which construct is superseded.
98 | |+[[code>>doc:sdmx:Glossary 2\.1.Code.WebHome]]|(% style="width:564px" %)Association to the [[Code>>doc:sdmx:Glossary 2\.1.Code.WebHome]] that is used at the specific point in the [[hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]].
99 | |+child|(% style="width:564px" %)Association to a child [[Code>>doc:sdmx:Glossary 2\.1.Code.WebHome]] in the [[hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]].
100 | |+(% style="color:#e74c3c" %)level|(% style="width:564px" %)Association to a (% style="color:#e74c3c" %)Level(%%) where (% style="color:#e74c3c" %)levels(%%) have been defined for the [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]].
101 |[[Code>>doc:sdmx:Glossary 2\.1.Code.WebHome]]| |(% style="width:564px" %)The [[Code>>doc:sdmx:Glossary 2\.1.Code.WebHome]] to be used at this point in the [[hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]].
102 | |/items|(% style="width:564px" %)Association to the [[Code list>>doc:sdmx:Glossary 2\.1.Code list.WebHome]] containing the [[Code>>doc:sdmx:Glossary 2\.1.Code.WebHome]].
103 |[[Codelist>>doc:sdmx:Glossary 2\.1.Code list.WebHome]]| |(% style="width:564px" %)The [[Code list>>doc:sdmx:Glossary 2\.1.Code list.WebHome]] containing the [[Code>>doc:sdmx:Glossary 2\.1.Code.WebHome]].
104 |HierarchyAssociation|(((
105 Inherits from:
106 //MaintainableArtefact//
107 )))|(% style="width:564px" %)An association between an [[Identifiable Artefact>>doc:sdmx:Glossary 2\.1.Identifiable artefact.WebHome]] and a [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]], within a specific context.
108 | |+contextObject|(% style="width:564px" %)The context within which the association is performed.
109 | |+linkedObject|(% style="width:564px" %)Associates the [[Identifiable Artefact>>doc:sdmx:Glossary 2\.1.Identifiable artefact.WebHome]] that needs the [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]].
110 | |+linkedHierarchy|(% style="width:564px" %)Associated the [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]].
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