[0.9.4.1] 'order by time desc' query does not order by time with different tags

[mblackstock]

Testing out #2022 I came across this problem. Version 0.9.4-rc1

Using CLI:

> insert test-sensor value=12
> insert test-sensor value=13
> insert test-sensor value=14
> insert test-sensor value=15
> insert test-sensor,tag=example value=16
> select * from "test-sensor" order by time desc;
name: test-sensor
-----------------
time                tag value
2015-09-11T04:08:33.108825071Z      15
2015-09-11T04:08:30.996790711Z      14
2015-09-11T04:08:29.676833764Z      13
2015-09-11T04:08:59.500124703Z  example 16
2015-09-11T04:08:27.837381605Z      12

Note that most recently added point is 4th in the list. Adding another point with a different tag:

> insert test-sensor,tag2=example2 value=17
> select * from "test-sensor" order by time desc;
name: test-sensor
-----------------
time                tag tag2        value
2015-09-11T04:08:33.108825071Z              15
2015-09-11T04:08:30.996790711Z              14
2015-09-11T04:08:29.676833764Z              13
2015-09-11T04:15:14.500959481Z      example2    17
2015-09-11T04:08:59.500124703Z  example         16
2015-09-11T04:08:27.837381605Z              12

Note that most recently added point is again 4th in the list.

[mblackstock]

Seeming related problem today in case it helps track this issue down.

I'm finding it hard to reproduce, but when I selected data in time ascending order (default) I get all of the data. When I queried in reverse order, I get only two points (see below). Tried the same query again later, and all of the data came in, but with the order messed up as previously reported (below)

> select * from "test-sensor-3";
name: test-sensor-3
-------------------
time                lat lng sensor_id   sensor_name tag value
2015-09-10T20:08:28.975Z            55      test-sensor-3       33
2015-09-10T20:08:33.089Z            55      test-sensor-3       33
2015-09-10T20:08:33.853Z            55      test-sensor-3       33
2015-09-10T21:05:42.792Z            55      test-sensor-3       33.5
2015-09-10T21:18:28.038513909Z                          example 33
2015-09-10T22:11:32.837607829Z                  test-sensor-3   example 33
2015-09-11T00:48:58.924000001Z                              99
2015-09-11T18:01:52.093000001Z  49  123                     12
2015-09-11T18:02:18.138000001Z  49  123                     12
2015-09-11T18:03:02.085000001Z  49  123                     12
2015-09-11T18:03:03.461000001Z  49  123                     12
2015-09-11T18:03:04.612000001Z  49  123                     12
2015-09-11T18:05:22.531000001Z  49  123                     12

> select * from "test-sensor-3" order by time desc limit 1000;
name: test-sensor-3
-------------------
time                lat lng sensor_id   sensor_name tag value
2015-09-10T22:11:32.837607829Z                  test-sensor-3   example 33
2015-09-10T21:18:28.038513909Z

later:

> select * from "test-sensor-3" order by time desc;
name: test-sensor-3
-------------------
time                lat lng sensor_id   sensor_name tag value
2015-09-10T22:11:32.837607829Z                  test-sensor-3   example 33
2015-09-11T18:08:30.275000001Z                              12
2015-09-11T18:08:15.035000001Z                              12
2015-09-11T18:05:22.531000001Z  49  123                     12
2015-09-11T18:03:04.612000001Z  49  123                     12
2015-09-11T18:03:03.461000001Z  49  123                     12
2015-09-11T18:03:02.085000001Z  49  123                     12
2015-09-11T18:02:18.138000001Z  49  123                     12
2015-09-11T18:01:52.093000001Z  49  123                     12
2015-09-11T00:48:58.924000001Z                              99
2015-09-10T21:18:28.038513909Z                          example 33
2015-09-10T21:05:42.792Z            55      test-sensor-3       33.5
2015-09-10T20:08:33.853Z            55      test-sensor-3       33
2015-09-10T20:08:33.089Z            55      test-sensor-3       33
2015-09-10T20:08:28.975Z            55      test-sensor-3       33

[hkrizek]

+1

[richterger]

I see the same issue here. As soon as a new tag comes in, sorting in descending order gets confused.

I looks a little bit to me, like every time a new tag comes in, it starts a new "group" that is sorted on it's own.

[rackunits]

+1

[beckettsean]

closing in favor of #4235, which although newer, has more conversation