record-key

Date: 2026-09-10. Status: implemented.

Decision. The primary key is normalised postcode plus introduction date. Deletion date, user type and release are attributes.

Reason. Unique across all 247,773 records in SPD 2026/2. Postcode alone repeats up to seven times.

Evidence. SIMD_Plan_Gap_Closure.md section 6. Validated on every release; never silently deduplicated.

Columns (67): CensusHouseholdCount1991, CensusHouseholdCount2001, CensusHouseholdCount2011, CensusHouseholdCount2022, CensusPopulationCount1991, CensusPopulationCount2001, CensusPopulationCount2011, CensusPopulationCount2022, CivilParish1930Code, CouncilArea2019Code, DataZone2001Code, DataZone2011Code, DataZone2022Code, DateOfDeletion, DateOfIntroduction, ElectoralWard2022Code, EnterpriseRegion2008Code, GridLinkIndicator, GridLinkPositionalAccuracy, GridReferenceEasting, GridReferenceNorthing, HealthBoardArea1995Code, HealthBoardArea2006Code, HealthBoardArea2019Code, ITL2025Level2Code, ITL2025Level3Code, IntegrationAuthority2019Code, IntermediateZone2001Code, IntermediateZone2011Code, IntermediateZone2022Code, IslandCode, LAU2025Level1Code, Latitude, LinkedSmallUserPostcode, LocalGovernmentDistrict1991Code, LocalGovernmentDistrict1995Code, Locality1991Code, Locality2001Code, Locality2020Code, Locality2022Code, Longitude, NationalPark2010Code, NeverDigitised, OutputArea1991Code, OutputArea2001Code, OutputArea2011Code, OutputArea2022Code, Postcode, PostcodeDistrict, PostcodeSector, ROACommunityPlanningPartnership2006Code, ROALocal2006Code, RegistrationDistrict2007Code, ScottishIndexOfMultipleDeprivation2020Rank, ScottishParliamentaryConstituency2026Code, ScottishParliamentaryRegion2026Code, Settlement2001Code, Settlement2020Code, Settlement2022Code, SplitIndicator, StrategicDevelopmentPlanningArea2013Code, TravelToWorkArea2011Code, UKParliamentaryConstituency2024Code, UrbanRural6Fold2022Code, UrbanRural8Fold2022Code, introduced_on, pc_norm