Wiki source code of 8 Hierarchy

Version 18.1 by Helena K. on 2026/06/05 13:08

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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
15.2	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.
1.1	8
18.1	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]].
1.1	10
15.1	11	The principal features of the [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] are:
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15.2	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]].
15.1	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 ==
1.1	19
3.2	20	=== 8.2.1 Class Diagram ===
1.1	21
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 ===
1.1	27
3.2	28	==== 8.2.2.1 Narrative ====
1.1	29
16.1	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]]//.
1.1	31
16.1	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.
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3.2	34	==== 8.2.2.2 Definitions ====
1.1	35
15.1	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 ===
1.1	47
3.2	48	==== 8.3.2.1 Narrative ====
1.1	49
15.1	50	The basic principles of the [[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]] are:
1.1	51
16.1	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.
1.1	55
16.1	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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16.1	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).
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16.1	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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16.1	62	The Level may have CodingFormat information defined (e.g. coding [[type>>doc:IMElements.type.WebHome]] at that level).
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16.1	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]].
1.1	65
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
15.1	70	\|[[Hierarchy>>doc:sdmx:Glossary 2\.1.Hierarchy.WebHome]]\|(((
1.1	71	Inherits from:
16.1	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.
3.3	74	\| \|hasFormalLevels\|(% style="width:564px" %)(((
16.1	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.
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16.1	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.
1.1	78	)))
16.1	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\|(((
1.1	82	Inherits from
16.1	83	//[[NameableArtefact>>doc:IMElements.AnnotableArtefact.IdentifiableArtefact.NameableArtefact.WebHome]]//
3.3	84	)))\|(% style="width:564px" %)(((
16.1	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.
1.1	87	)))
15.1	88	\| \|+codeFormat\|(% style="width:564px" %)Association to the [[Coding Format>>doc:sdmx:Glossary 2\.1.Coding format.WebHome]].
16.1	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.
1.1	100	\|HierarchyAssociation\|(((
	101	Inherits from:
16.1	102	//[[MaintainableArtefact>>doc:IMElements.AnnotableArtefact.IdentifiableArtefact.NameableArtefact.VersionableArtefact.MaintainableArtefact.WebHome]]//
15.1	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.
15.1	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]].