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Note
icon false title Important Note
Transitive Closure Files are not distributed in the SNOMED CT International Release The file structures documented here are points of reference for those generating transitive closure table from release data. SNOMED International provides a script file that can be used to generate the Snapshot Transitive Closure file from the snapshot Relationship File.

The

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SpacePreSpace truefalse t Transitive Closure

is the complete set of

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SpacePreSpace truefalse t relationships

between every

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and each of its super-type

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, in other words both its parents and

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.

A transitive closure table is one of the most efficient ways to test for subsumption between concepts.

Snapshot Transitive Closure File

SNOMED International provides an example of a Transitive Closure Perl script file that can be used to generating a snapshot view of the transitive closure from the snapshot release of the 

Specref
RefType file t Relationship

. The output of this script conforms to the following following file structure. Note that the primary key for this table consists of both columns.

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Versioned Transitive Closure

A versioned view of the

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SpacePreSpace truefalse t Transitive Closure

can also be generated by combining the snapshot views for different effective times and removing redundant rows (e.g. where the transitive closure has not changed between release versions). The generated file could then be represented using the example specification below. Note that the unique key for this file would consist of the subtypeId, supertypeId and effectiveTime.

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Start filespec Page REUSE:Transitive Closure File

Related Links

• 7.5.2 Transitive closure implementation

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