{"data":{"schemaVersion":"realm.temporal-relationships.v1","temporalSemantics":{"validTime":{"granularity":"date","bounds":"inclusive","nullStart":"start date not published in the upstream history row","nullEnd":"open-ended in the upstream history row; not independent proof of present control"},"transactionTime":{"observedAt":"2026-10-17T05:35:58.500035+00:00","meaning":"time the checksum-addressed MDRS artifacts were observed by the PostgreSQL ingestion"},"derivation":{"controllerControlsOperator":"intersection of controller and operator valid-time intervals evidenced through this mine","currentIdentity":"current controller and operator are asserted only by the MDRS Mines snapshot"}},"current":{"mine":{"type":"mine","id":"1900362","name":"Boxborough Pit And Mill"},"operator":{"type":"operator","id":"L03402","name":"W D Chisholm Company"},"controller":{"type":"controller","id":"M02724","name":"Chisholm W D"},"source":{"datasetId":"msha-mines","observedAt":"2026-10-17T05:35:58.500035+00:00"}},"edges":[{"type":"operator_operates_mine","subject":{"type":"operator","id":"L03401","name":"Stow Sand & Gravel Inc"},"object":{"type":"mine","id":"1900362","name":"Boxborough Pit And Mill"},"validFrom":"1950-01-01","validTo":"1979-06-30","current":false,"derived":false,"source":{"datasetId":"msha-controller-operator-history","observedAt":"2026-10-17T05:35:58.500035+00:00","recordKey":"1900362|L03401|1950-01-01|1979-06-30"}},{"type":"controller_controls_mine","subject":{"type":"controller","id":"M02723","name":"Bry Irene K"},"object":{"type":"mine","id":"1900362","name":"Boxborough Pit And Mill"},"validFrom":"1950-01-01","validTo":"1979-06-30","current":false,"derived":false,"source":{"datasetId":"msha-controller-operator-history","observedAt":"2026-10-17T05:35:58.500035+00:00","recordKey":"1900362|M02723|1950-01-01|1979-06-30"}},{"type":"controller_controls_operator","subject":{"type":"controller","id":"M02723","name":"Bry Irene K"},"object":{"type":"operator","id":"L03401","name":"Stow Sand & Gravel Inc"},"validFrom":"1950-01-01","validTo":"1979-06-30","current":false,"derived":true,"evidenceMineId":"1900362","intervalAnomaly":false,"source":{"datasetId":"msha-controller-operator-history","observedAt":"2026-10-17T05:35:58.500035+00:00","recordKey":"1900362|L03401|1950-01-01|M02723|1950-01-01|126750"}},{"type":"operator_operates_mine","subject":{"type":"operator","id":"L03402","name":"W D Chisholm Company"},"object":{"type":"mine","id":"1900362","name":"Boxborough Pit And Mill"},"validFrom":"1979-07-01","validTo":null,"current":true,"derived":false,"source":{"datasetId":"msha-controller-operator-history","observedAt":"2026-10-17T05:35:58.500035+00:00","recordKey":"1900362|L03402|1979-07-01|"}},{"type":"controller_controls_mine","subject":{"type":"controller","id":"M02724","name":"Chisholm W D"},"object":{"type":"mine","id":"1900362","name":"Boxborough Pit And Mill"},"validFrom":"1979-07-01","validTo":null,"current":true,"derived":false,"source":{"datasetId":"msha-controller-operator-history","observedAt":"2026-10-17T05:35:58.500035+00:00","recordKey":"1900362|M02724|1979-07-01|"}},{"type":"controller_controls_operator","subject":{"type":"controller","id":"M02724","name":"Chisholm W D"},"object":{"type":"operator","id":"L03402","name":"W D Chisholm Company"},"validFrom":"1979-07-01","validTo":null,"current":true,"derived":true,"evidenceMineId":"1900362","intervalAnomaly":false,"source":{"datasetId":"msha-controller-operator-history","observedAt":"2026-10-17T05:35:58.500035+00:00","recordKey":"1900362|L03402|1979-07-01|M02724|1979-07-01|126751"}}],"coverage":{"historyRecords":2,"edgeCount":6,"intervalAnomalies":0,"sourceDatasetId":"msha-controller-operator-history"}},"meta":{"mineId":"1900362","dataSource":"postgres","snapshotId":"2026-10-17T05:35:58.500035+00:00","completedAt":"2026-10-17T06:17:15.228Z","sourceCount":20,"totalRows":15450873,"relationshipSemantics":"valid time; null validTo means current or open-ended in the source"}}