How should I modify this query so it only reports the last/newest samples of an instance. In the current query some instances are listed twice.
SELECT * FROM “ceph_value” WHERE “type” = ‘ceph_bytes’ AND “type_instance” = ‘Osd.numpg’ AND “value” > 0 AND time > now() - 30s ORDER BY time DESC LIMIT 40
time host instance type type_instance value
---- ---- -------- ---- ------------- -----
2018-01-10T09:38:27.524637642Z c03 osd.5 ceph_bytes Osd.numpg 155
2018-01-10T09:38:27.518771543Z c03 osd.2 ceph_bytes Osd.numpg 52
2018-01-10T09:38:24.625571475Z c01 osd.0 ceph_bytes Osd.numpg 129
2018-01-10T09:38:24.621389891Z c01 osd.3 ceph_bytes Osd.numpg 51
2018-01-10T09:38:24.215214993Z c02 osd.4 ceph_bytes Osd.numpg 142
2018-01-10T09:38:24.210770483Z c02 osd.1 ceph_bytes Osd.numpg 44
2018-01-10T09:38:17.522840089Z c03 osd.5 ceph_bytes Osd.numpg 155
2018-01-10T09:38:17.517757301Z c03 osd.2 ceph_bytes Osd.numpg 52
2018-01-10T09:38:14.634087585Z c01 osd.7 ceph_bytes Osd.numpg 56
2018-01-10T09:38:14.625388215Z c01 osd.0 ceph_bytes Osd.numpg 129
2018-01-10T09:38:14.621325111Z c01 osd.3 ceph_bytes Osd.numpg 51
2018-01-10T09:38:14.215173666Z c02 osd.4 ceph_bytes Osd.numpg 142
2018-01-10T09:38:14.210634992Z c02 osd.1 ceph_bytes Osd.numpg 44
2018-01-10T09:38:07.523106781Z c03 osd.5 ceph_bytes Osd.numpg 155
2018-01-10T09:38:07.517833556Z c03 osd.2 ceph_bytes Osd.numpg 52
