BEGIN;

DO $$
BEGIN
  IF EXISTS (
    SELECT 1
    FROM "materials"
    WHERE "uploadId" IS NOT NULL
      AND "deletedAt" IS NULL
    GROUP BY "uploadId"
    HAVING COUNT(*) > 1
  ) THEN
    RAISE EXCEPTION 'active materials contain duplicate uploadId values; refusing to rebuild materials_uploadId_key';
  END IF;
END
$$;

DROP INDEX IF EXISTS "materials_uploadId_key";

CREATE UNIQUE INDEX "materials_uploadId_key"
ON "materials" USING btree ("uploadId")
WHERE "uploadId" IS NOT NULL AND "deletedAt" IS NULL;

COMMIT;