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Wiki source code of 8 Hierarchy

Version 18.1 by Helena K. on 2026/06/05 13:08
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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 and restricts any [[child>>doc:IMElements.child.WebHome]] [[Code>>doc:IMElements.AnnotableArtefact.IdentifiableArtefact.NameableArtefact.Item.Code.WebHome]] to having just one [[parent>>doc:IMElements.parent.WebHome]] [[Code>>doc:IMElements.AnnotableArtefact.IdentifiableArtefact.NameableArtefact.Item.Code.WebHome]]. Whilst this [[structure>>doc:IMElements.structure.WebHome]] is useful for supporting the needs of the [[DataStructureDefinition>>doc:IMElements.AnnotableArtefact.IdentifiableArtefact.NameableArtefact.VersionableArtefact.MaintainableArtefact.Structure.DataStructureDefinition.WebHome]] and the [[MetadataStructureDefinition>>doc:IMElements.AnnotableArtefact.IdentifiableArtefact.NameableArtefact.VersionableArtefact.MaintainableArtefact.Structure.MetadataStructureDefinition.WebHome]], it may not be sufficient for supporting the more complex associations between codes 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>>doc:IMElements.AnnotableArtefact.IdentifiableArtefact.NameableArtefact.VersionableArtefact.MaintainableArtefact.Structure.DataStructureDefinition.WebHome]] 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>>doc:IMElements.AnnotableArtefact.IdentifiableArtefact.NameableArtefact.VersionableArtefact.MaintainableArtefact.Structure.DataStructureDefinition.WebHome]]. A [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] may be linked to an IndentifiableArtefact, in order to assist.
8
9 Note that a [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] is not necessarily a balanced tree. A balanced tree is where levels are pre-defined and fixed, (i.e. a level always has the same set of codes, and any code has a fixed [[parent>>doc:IMElements.parent.WebHome]] and [[child>>doc:IMElements.child.WebHome]] relationship to other codes). 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]].
10
11 The principal features of the [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] are:
12
13 1. A [[child>>doc:IMElements.child.WebHome]] code can have more than one [[parent>>doc:IMElements.parent.WebHome]].
14 1. There can be more than one code that has no [[parent>>doc:IMElements.parent.WebHome]] (i.e. more than one “root node”).
15 1. The 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>>doc:IMElements.parent.WebHome]]/[[child>>doc:IMElements.child.WebHome]] relationships in the coding [[structure>>doc:IMElements.structure.WebHome]].
16 1. [[Hierarchies>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] may be associated to the structures they refer to, via the HierarchyAssociation.
17
18 == 8.2 Inheritance ==
19
20 === 8.2.1 Class Diagram ===
21
22 [[image:image61.png]]
23
24 **Figure 35: Inheritance class diagram for the Hierarchy**
25
26 === 8.2.2 Explanation of the Diagram ===
27
28 ==== 8.2.2.1 Narrative ====
29
30 The [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] and //HierarchyAssociation// inherit from //[[MaintainableArtefact>>doc:IMElements.AnnotableArtefact.IdentifiableArtefact.NameableArtefact.VersionableArtefact.MaintainableArtefact.WebHome]]// and thus have identification, naming, versioning and a [[maintenance agency>>doc:sdmx:Glossary 2\.1.Maintenance agency.WebHome]]. The Level is a //[[NameableArtefact>>doc:IMElements.AnnotableArtefact.IdentifiableArtefact.NameableArtefact.WebHome]]// and therefore has an Id, multi-lingual [[name>>doc:IMElements.name.WebHome]] and multi-lingual [[description>>doc:IMElements.description.WebHome]]. A //HierachicalCode// is an //[[IdentifiableArtefact>>doc:IMElements.AnnotableArtefact.IdentifiableArtefact.WebHome]]//.
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32 It is important to understand that the Codes 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.
33
34 ==== 8.2.2.2 Definitions ====
35
36 The definitions of the various classes, [[attributes>>doc:sdmx:Glossary 2\.1.Attribute.WebHome]], and associations are shown in the relationship section below.
37
38 == 8.3 Relationship ==
39
40 === 8.3.1 Class Diagram ===
41
42 [[image:image62.png]]
43
44 **Figure 36: Relationship class diagram of the Hierarchy**
45
46 === 8.3.2 Explanation of the Diagram ===
47
48 ==== 8.3.2.1 Narrative ====
49
50 The basic principles of the [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] are:
51
52 1. The [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] is a specification of the [[structure>>doc:IMElements.structure.WebHome]] of the Codes.
53 1. The Codes 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>>doc:IMElements.references.WebHome]] to Codes in one or more external [[Codelists>>doc:sdmx:Glossary 2\.1.Code list.WebHome]].
54 1. The [[hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] of Codes is specified in HierarchicalCode. This [[references>>doc:IMElements.references.WebHome]] the [[Code>>doc:IMElements.AnnotableArtefact.IdentifiableArtefact.NameableArtefact.Item.Code.WebHome]] and its immediate [[child>>doc:IMElements.child.WebHome]] HierarchicalCodes.
55
56 A [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] can have formal levels (hasFormalLevels="true"). However, even if hasFormalLevels="false" the [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] can still have one or more Levels associated in order to document information about the HierarchicalCodes.
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58 If hasFormalLevels="false" the [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] is “[[value>>doc:IMElements.value.WebHome]] based” comprising a [[hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] of codes with no formal Levels. If hasFormalLevels="true" then the [[hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] is “level based” where each Level is a formal 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 “level based” [[hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] each HierarchicalCode is linked to the Level in which it resides. It is expected that all HierarchicalCodes at the same hierarchic level defined by the +[[parent>>doc:IMElements.parent.WebHome]]/+[[child>>doc:IMElements.child.WebHome]] association will be linked to the same Level. Note that the +level association need only be specified if the HierarchicalCode is at a different hierarchical level (implied by the HierarchicalCode [[parent>>doc:IMElements.parent.WebHome]]/[[child>>doc:IMElements.child.WebHome]] association) than the actual Level in the level [[hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] (implied by the Level [[parent>>doc:IMElements.parent.WebHome]]/[[child>>doc:IMElements.child.WebHome]] association).
59
60 [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 Level, where Levels are numbered consecutively starting with level 1 at the highest Level].
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62 The Level may have CodingFormat information defined (e.g. coding [[type>>doc:IMElements.type.WebHome]] at that level).
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64 A HierarchyAssociation links an [[IdentifiableArtefact>>doc:IMElements.AnnotableArtefact.IdentifiableArtefact.WebHome]] (+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:IMElements.AnnotableArtefact.IdentifiableArtefact.Component.DimensionComponent.Dimension.WebHome]] in the context of a [[Dataflow>>doc:IMElements.AnnotableArtefact.IdentifiableArtefact.NameableArtefact.VersionableArtefact.MaintainableArtefact.StructureUsage.Dataflow.WebHome]].
65
66 ==== 8.3.2.2 Definitions ====
67
68 (% style="width:901.835px" %)
69 |**Class**|**Feature**|(% style="width:564px" %)**Description**
70 |[[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]]|(((
71 Inherits from:
72 //[[MaintainableArtefact>>doc:IMElements.AnnotableArtefact.IdentifiableArtefact.NameableArtefact.VersionableArtefact.MaintainableArtefact.WebHome]]//
73 )))|(% style="width:564px" %)A [[classification>>doc:sdmx:Glossary 2\.1.Statistical Classification.WebHome]] structure arranged in levels of detail from the broadest to the most detailed level.
74 | |hasFormalLevels|(% style="width:564px" %)(((
75 If “true”, this indicates a [[hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] where the structure is arranged in levels of detail from the broadest to the most detailed level.
76
77 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 level structure.
78 )))
79 | |+codes|(% style="width:564px" %)Association to the top-level [[Hierarchical Codes>>doc:sdmx:Glossary 2\.1.Hierarchical code.WebHome]] in the [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]].
80 | |+level|(% style="width:564px" %)Association to the top Level in the [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]].
81 |Level|(((
82 Inherits from
83 //[[NameableArtefact>>doc:IMElements.AnnotableArtefact.IdentifiableArtefact.NameableArtefact.WebHome]]//
84 )))|(% style="width:564px" %)(((
85 In a “level based” [[hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] this describes a group of Codes which are characterised by homogeneous coding, and where the parent of each Code in the group is at the same higher level of the [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]].
86 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 level.
87 )))
88 | |+codeFormat|(% style="width:564px" %)Association to the [[Coding Format>>doc:sdmx:Glossary 2\.1.Coding format.WebHome]].
89 | |+[[child>>doc:IMElements.child.WebHome]]|(% style="width:564px" %)Association to a child Level of Level.
90 |CodingFormat| |(% style="width:564px" %)Specifies format information for the codes at this level in the [[hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] such as whether the codes at the level are alphabetic, numeric or alphanumeric and the code length.
91 |HierarchicalCode| |(% style="width:564px" %)A hierarchic structure of code references.
92 | |[[validFrom>>doc:IMElements.validFrom.WebHome]]|(% style="width:564px" %)Date from which the construct is valid
93 | |[[validTo>>doc:IMElements.validTo.WebHome]]|(% style="width:564px" %)Date from which construct is superseded.
94 | |+code|(% style="width:564px" %)Association to the Code that is used at the specific point in the [[hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]].
95 | |+[[child>>doc:IMElements.child.WebHome]]|(% style="width:564px" %)Association to a child Code in the [[hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]].
96 | |+level|(% style="width:564px" %)Association to a Level where levels have been defined for the [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]].
97 |[[Code>>doc:IMElements.AnnotableArtefact.IdentifiableArtefact.NameableArtefact.Item.Code.WebHome]]| |(% style="width:564px" %)The Code to be used at this point in the [[hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]].
98 | |/[[items>>doc:IMElements.items.WebHome]]|(% style="width:564px" %)Association to the [[Code list>>doc:sdmx:Glossary 2\.1.Code list.WebHome]] containing the Code.
99 |[[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.
100 |HierarchyAssociation|(((
101 Inherits from:
102 //[[MaintainableArtefact>>doc:IMElements.AnnotableArtefact.IdentifiableArtefact.NameableArtefact.VersionableArtefact.MaintainableArtefact.WebHome]]//
103 )))|(% 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.
104 | |+contextObject|(% style="width:564px" %)The context within which the association is performed.
105 | |+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]].
106 | |+linkedHierarchy|(% style="width:564px" %)Associated the [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]].
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