ALTER TABLE assessor_import_processing_runs
  ADD CONSTRAINT assessor_processing_runs_identity_unique UNIQUE (id, project_id, artifact_id);

CREATE TABLE assessor_gpo_backup_instances (
  id text PRIMARY KEY CHECK (btrim(id) <> ''),
  project_id text NOT NULL,
  artifact_id text NOT NULL,
  processing_run_id text NOT NULL,
  instance_id text NOT NULL CHECK (btrim(instance_id) <> ''),
  created_at timestamptz NOT NULL,
  data jsonb NOT NULL CHECK (jsonb_typeof(data) = 'object'),
  FOREIGN KEY (processing_run_id, project_id, artifact_id)
    REFERENCES assessor_import_processing_runs(id, project_id, artifact_id) ON DELETE CASCADE,
  UNIQUE (processing_run_id, instance_id)
);

CREATE INDEX assessor_gpo_backup_instances_project_idx
  ON assessor_gpo_backup_instances(project_id, created_at, id);

CREATE INDEX assessor_gpo_backup_instances_artifact_idx
  ON assessor_gpo_backup_instances(artifact_id, processing_run_id, id);