=====Uniqueness=====

===Definition(s)===
  - Uniqueness of data records is the degree to which [[data_concept:data record|data records]] occur only once in a [[data_concept:data file|data file]].\\ 
  - Uniqueness of the mapping of an object in a data file is the degree to which [[data_concept:object|objects]] (in the real world) occur as one [[data_concept:data record|data record]] in a [[data_concept:data file|data file]].\\ 
  - Uniqueness of primary keys is the degree to which [[data_concept:primary key|primary keys]] occur only once in a [[data_concept:data file|data file]].

===Note===
In general, double [[data_concept:data record|data records]] should be deduplicated.

===Relation(s)===
|Uniqueness| is a [[general_term:characteristic|characteristic]] of |[[data_concept:data record|data records]]|
|Uniqueness| is a [[general_term:characteristic|characteristic]] of the mapping of [[data_concept:object|objects]] in a |[[data_concept:data file|data file]]|
|Uniqueness| is a [[general_term:characteristic|characteristic]] of |[[data_concept:primary key|primary keys]]|

===Example(s)===
  - This article appears twice in a [[data_concept:data file|data file]] under the same article number. This is easy to detect by checking on double article numbers.\\ 
  - This article appears twice in a [[data_concept:data file|data file]] under a different article number. This can only be discovered by comparison of other [[data_concept:data element|data elements]] than the article number.\\ 
  -  Two different articles appear  under the same article number in a [[data_concept:data file|data file]]. This can only be discovered by checking double article numbers and then compare other  [[data_concept:data element|data elements]] than article number before deduplicating.

===Reference(s)===
DAMA NL (2020). Dimensions of Data Quality (DDQ). Research paper. https://www.dama-nl.org/wp-content/uploads/2020/09/DDQ-Dimensions-of-Data-Quality-Research-Paper-version-1.2-d.d.-3-Sept-2020.pdf

{{tag>All DataQualityDimension}}