Wiki source code of 8 Hierarchy

Last modified by Helena K. on 2026/06/08 17:11

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3.2	1	{{box title="Contents"}}
	2	{{toc/}}
	3	{{/box}}
1.1	4
3.2	5	== 8.1 Scope ==
1.1	6
18.3	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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18.3	9	Note that a [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] is not necessarily a balanced tree. A balanced tree is where [[levels>>doc:sdmx:Glossary 2\.1.Level.WebHome]] are pre-defined and fixed, (i.e. a [[level>>doc:sdmx:Glossary 2\.1.Level.WebHome]] 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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18.3	11	The principal features of the [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] are:
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18.3	13	1. A child [[code>>doc:sdmx:Glossary 2\.1.Code.WebHome]] can have more than one parent.
	14	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”).
	15	1. The [[levels>>doc:sdmx:Glossary 2\.1.Level.WebHome]] 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.
	16	1. [[Hierarchies>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] may be associated to the structures they refer to, via the HierarchyAssociation.
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3.2	18	== 8.2 Inheritance ==
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3.2	20	=== 8.2.1 Class Diagram ===
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10.2	22	[[image:image61.png]]
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1.1	24	Figure 35: Inheritance class diagram for the Hierarchy
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3.2	26	=== 8.2.2 Explanation of the Diagram ===
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3.2	28	==== 8.2.2.1 Narrative ====
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18.4	30	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 [[Level>>doc:sdmx:Glossary 2\.1.Level.WebHome]] is a //NameableArtefact// and therefore has an Id, multi-lingual name and multi-lingual description. A //HierachicalCode// is an //IdentifiableArtefact//.
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18.4	32	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.
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3.2	34	==== 8.2.2.2 Definitions ====
1.1	35
18.4	36	The definitions of the various classes, [[attributes>>doc:sdmx:Glossary 2\.1.Attribute.WebHome]], and associations are shown in the relationship section below.
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3.2	38	== 8.3 Relationship ==
1.1	39
3.2	40	=== 8.3.1 Class Diagram ===
1.1	41
10.3	42	[[image:image62.png]]
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1.1	44	Figure 36: Relationship class diagram of the Hierarchy
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3.2	46	=== 8.3.2 Explanation of the Diagram ===
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3.2	48	==== 8.3.2.1 Narrative ====
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18.4	50	The basic principles of the [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] are:
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18.4	52	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]].
	53	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]].
	54	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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18.4	56	A [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] can have formal [[levels>>doc:sdmx:Glossary 2\.1.Level.WebHome]] (hasFormalLevels="true"). However, even if hasFormalLevels="false" the [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] can still have one or more [[Levels>>doc:sdmx:Glossary 2\.1.Level.WebHome]] associated in order to document information about the HierarchicalCodes.
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18.4	58	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 [[Levels>>doc:sdmx:Glossary 2\.1.Level.WebHome]]. If hasFormalLevels="true" then the [[hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] is “[[level>>doc:sdmx:Glossary 2\.1.Level.WebHome]] based” where each [[Level>>doc:sdmx:Glossary 2\.1.Level.WebHome]] is a formal [[Level>>doc:sdmx:Glossary 2\.1.Level.WebHome]] 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>>doc:sdmx:Glossary 2\.1.Level.WebHome]] based” [[hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] each HierarchicalCode is linked to the [[Level>>doc:sdmx:Glossary 2\.1.Level.WebHome]] in which it resides. It is expected that all HierarchicalCodes at the same hierarchic [[level>>doc:sdmx:Glossary 2\.1.Level.WebHome]] defined by the +parent/+child association will be linked to the same [[Level>>doc:sdmx:Glossary 2\.1.Level.WebHome]]. Note that the +[[level>>doc:sdmx:Glossary 2\.1.Level.WebHome]] association need only be specified if the HierarchicalCode is at a different hierarchical [[level>>doc:sdmx:Glossary 2\.1.Level.WebHome]] (implied by the HierarchicalCode parent/child association) than the actual [[Level>>doc:sdmx:Glossary 2\.1.Level.WebHome]] in the [[level>>doc:sdmx:Glossary 2\.1.Level.WebHome]] [[hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] (implied by the [[Level>>doc:sdmx:Glossary 2\.1.Level.WebHome]] parent/child association).
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18.4	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>>doc:sdmx:Glossary 2\.1.Level.WebHome]], where [[Levels>>doc:sdmx:Glossary 2\.1.Level.WebHome]] are numbered consecutively starting with [[level>>doc:sdmx:Glossary 2\.1.Level.WebHome]] 1 at the highest [[Level>>doc:sdmx:Glossary 2\.1.Level.WebHome]]].
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18.4	62	The [[Level>>doc:sdmx:Glossary 2\.1.Level.WebHome]] may have CodingFormat information defined (e.g. coding type at that [[level>>doc:sdmx:Glossary 2\.1.Level.WebHome]]).
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18.4	64	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]].
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16.1	66	==== 8.3.2.2 Definitions ====
1.1	67
3.3	68	(% style="width:901.835px" %)
	69	\|Class\|Feature\|(% style="width:564px" %)Description
18.4	70	\|[[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]]\|(((
1.1	71	Inherits from:
18.2	72	//MaintainableArtefact//
18.5	73	)))\|(% style="width:564px" %)A [[classification>>doc:sdmx:Glossary 2\.1.Statistical Classification.WebHome]] structure arranged in [[levels>>doc:sdmx:Glossary 2\.1.Level.WebHome]] of detail from the broadest to the most detailed [[level>>doc:sdmx:Glossary 2\.1.Level.WebHome]].
3.3	74	\| \|hasFormalLevels\|(% style="width:564px" %)(((
18.5	75	If “true”, this indicates a [[hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] where the structure is arranged in [[levels>>doc:sdmx:Glossary 2\.1.Level.WebHome]] of detail from the broadest to the most detailed [[level>>doc:sdmx:Glossary 2\.1.Level.WebHome]].
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18.5	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>>doc:sdmx:Glossary 2\.1.Level.WebHome]] structure.
1.1	78	)))
18.5	79	\| \|+codes\|(% style="width:564px" %)Association to the top-[[level>>doc:sdmx:Glossary 2\.1.Level.WebHome]] [[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>>doc:sdmx:Glossary 2\.1.Level.WebHome]] in the [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]].
	81	\|[[Level>>doc:sdmx:Glossary 2\.1.Level.WebHome]]\|(((
1.1	82	Inherits from
18.2	83	//NameableArtefact//
3.3	84	)))\|(% style="width:564px" %)(((
18.5	85	In a “[[level>>doc:sdmx:Glossary 2\.1.Level.WebHome]] 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 [[level>>doc:sdmx:Glossary 2\.1.Level.WebHome]] 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>>doc:sdmx:Glossary 2\.1.Level.WebHome]].
1.1	87	)))
18.4	88	\| \|+codeFormat\|(% style="width:564px" %)Association to the [[Coding Format>>doc:sdmx:Glossary 2\.1.Coding format.WebHome]].
18.5	89	\| \|+child\|(% style="width:564px" %)Association to a child [[Level>>doc:sdmx:Glossary 2\.1.Level.WebHome]] of [[Level>>doc:sdmx:Glossary 2\.1.Level.WebHome]].
	90	\|CodingFormat\| \|(% style="width:564px" %)Specifies format information for the [[codes>>doc:sdmx:Glossary 2\.1.Code.WebHome]] at this [[level>>doc:sdmx:Glossary 2\.1.Level.WebHome]] in the [[hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] such as whether the [[codes>>doc:sdmx:Glossary 2\.1.Code.WebHome]] at the [[level>>doc:sdmx:Glossary 2\.1.Level.WebHome]] are alphabetic, numeric or alphanumeric and the [[code>>doc:sdmx:Glossary 2\.1.Code.WebHome]] length.
18.4	91	\|HierarchicalCode\| \|(% style="width:564px" %)A hierarchic structure of [[code>>doc:sdmx:Glossary 2\.1.Code.WebHome]] references.
18.2	92	\| \|validFrom\|(% style="width:564px" %)Date from which the construct is valid
	93	\| \|validTo\|(% style="width:564px" %)Date from which construct is superseded.
18.4	94	\| \|+code\|(% 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]].
	95	\| \|+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]].
18.5	96	\| \|+level\|(% style="width:564px" %)Association to a [[Level>>doc:sdmx:Glossary 2\.1.Level.WebHome]] where [[levels>>doc:sdmx:Glossary 2\.1.Level.WebHome]] have been defined for the [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]].
18.4	97	\|[[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]].
	98	\| \|/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]].
	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>>doc:sdmx:Glossary 2\.1.Code.WebHome]].
1.1	100	\|HierarchyAssociation\|(((
	101	Inherits from:
18.2	102	//MaintainableArtefact//
18.4	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.
3.3	104	\| \|+contextObject\|(% style="width:564px" %)The context within which the association is performed.
18.4	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]].