Andrew Lamb created ARROW-12159:
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Summary: [Rust][DataFusion] Support grouping on expressions
Key: ARROW-12159
URL: https://issues.apache.org/jira/browse/ARROW-12159
Project: Apache Arrow
Issue Type: New Feature
Reporter: Andrew Lamb
Usecase:
I want to group based on time windows (as defined by the `date_trunc`
function).
For example, given the table:
{code}
+------+-------------------+---------------------+-------------+------------------+-------------------+--------------+-----------+------------+---------------+-------------+--------------------+--------------------+
| cpu | host | time | usage_guest |
usage_guest_nice | usage_idle | usage_iowait | usage_irq | usage_nice |
usage_softirq | usage_steal | usage_system | usage_user |
+------+-------------------+---------------------+-------------+------------------+-------------------+--------------+-----------+------------+---------------+-------------+--------------------+--------------------+
| cpu0 | MacBook-Pro.local | 1617130130000000000 | 0 | 0
| 65.30408773649165 | 0 | 0 | 0 | 0 |
0 | 18.444666002000673 | 16.251246261217506 |
| cpu1 | MacBook-Pro.local | 1617130130000000000 | 0 | 0
| 84.43113772402216 | 0 | 0 | 0 | 0 |
0 | 3.193612774446795 | 12.37524950097282 |
| cpu2 | MacBook-Pro.local | 1617130130000000000 | 0 | 0
| 65.96806387199344 | 0 | 0 | 0 | 0 |
0 | 15.469061876247794 | 18.56287425146831 |
| cpu3 | MacBook-Pro.local | 1617130130000000000 | 0 | 0
| 84.0478564307993 | 0 | 0 | 0 | 0 |
0 | 3.0907278165770684 | 12.861415752863932 |
| cpu4 | MacBook-Pro.local | 1617130130000000000 | 0 | 0
| 63.21036889281897 | 0 | 0 | 0 | 0 |
0 | 13.758723828377473 | 23.030907278223218 |
| cpu5 | MacBook-Pro.local | 1617130130000000000 | 0 | 0
| 83.94815553242313 | 0 | 0 | 0 | 0 |
0 | 2.991026919231221 | 13.0608175473346 |
| cpu6 | MacBook-Pro.local | 1617130130000000000 | 0 | 0
| 70.85828343276965 | 0 | 0 | 0 | 0 |
0 | 12.87425149699077 | 16.26746506987651 |
| cpu7 | MacBook-Pro.local | 1617130130000000000 | 0 | 0
| 83.9321357287122 | 0 | 0 | 0 | 0 |
0 | 3.093812375243205 | 12.974051896176206 |
| cpu8 | MacBook-Pro.local | 1617130130000000000 | 0 | 0
| 74.80079681313936 | 0 | 0 | 0 | 0 |
0 | 10.756972111708253 | 14.442231075949556 |
| cpu9 | MacBook-Pro.local | 1617130130000000000 | 0 | 0
| 83.84845463618315 | 0 | 0 | 0 | 0 |
0 | 3.0907278165434624 | 13.060817547316466 |
+------+-------------------+---------------------+-------------+------------------+-------------------+--------------+-----------+------------+---------------+-------------+--------------------+--------------------+
{code}
I want to be able to find the min and max usage time grouped by minute
{code}
select
date_trunc('minute', cast (time as timestamp)),
min(usage_user),
max(usage_user)
from
cpu
group by
date_trunc('minute', cast (time as timestamp)), min(usage_user)"
{code}
Or alternately
{code}
select
date_trunc('minute', cast (time as timestamp)),
min(usage_user),
max(usage_user)
from
cpu
group by
1
{code}
{code}Instead as of now I get a planning error:
Error preparing query Error during planning: Projection references
non-aggregate values
{code}
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