Your query is syntactically correct but returned no results
SELECT mean("tup_inserted") AS "mean_tup_inserted"
FROM "telegraf"."autogen"."postgresql"
WHERE time > '2018-10-04T13:08:00.000Z'
AND time < '2018-10-04T13:08:00.000Z'
AND "db"='db_sige_mes_2018'
GROUP BY time(:interval:) FILL(null)