Datetime transform functions

[richardstartin]

This PR starts with a small refactoring to allow TransformFunctionTypes to have aliases, then introduces TransformFunctions for the following functions:

• year
• yearOfWeek
• yow
• month
• week
• weekOfYear
• quarter
• dayOfWeek
• dow
• dayOfYear
• doy
• dayOfMonth
• day
• hour
• minute
• millisecond

The transform functions are tested against the @ScalarFunctions.

The motivation for the change is the high cost of using scalar functions in transforms. Here is the allocation rate observed for

select count(*), year(event_time) as y, month(event_time) as m from githubEvents group by y, m

vs the similar

select count(*), dateTrunc('year', event_time) as y, dateTrunc('m', event_time) as y from githubEvents group by y, m

When scalar function is used, 16% of samples were in verifying accessibility of the Method - @ScalarFunction should be used only as a last resort.

[richardstartin]

I've reverted to JODA because I noticed that DateTime objects appear to scalarise in loops like this, where java.time results in allocation. I only tested for year but the difference is big enough to stay on JODA:

Benchmark                                                      (_size)  Mode  Cnt       Score       Error   Units
BenchmarkTimeAPI.convertJavaTime                                  1024  avgt    5      35.190 ±     1.019   us/op
BenchmarkTimeAPI.convertJavaTime:·gc.alloc.rate                   1024  avgt    5    3842.276 ±   112.354  MB/sec
BenchmarkTimeAPI.convertJavaTime:·gc.alloc.rate.norm              1024  avgt    5  212992.015 ±     0.002    B/op
BenchmarkTimeAPI.convertJavaTime:·gc.churn.G1_Eden_Space          1024  avgt    5    3845.330 ±   353.367  MB/sec
BenchmarkTimeAPI.convertJavaTime:·gc.churn.G1_Eden_Space.norm     1024  avgt    5  213156.517 ± 17414.389    B/op
BenchmarkTimeAPI.convertJavaTime:·gc.churn.G1_Old_Gen             1024  avgt    5       0.003 ±     0.009  MB/sec
BenchmarkTimeAPI.convertJavaTime:·gc.churn.G1_Old_Gen.norm        1024  avgt    5       0.190 ±     0.510    B/op
BenchmarkTimeAPI.convertJavaTime:·gc.count                        1024  avgt    5      91.000              counts
BenchmarkTimeAPI.convertJavaTime:·gc.time                         1024  avgt    5      54.000                  ms
BenchmarkTimeAPI.convertJodaTime                                  1024  avgt    5       6.541 ±     0.302   us/op
BenchmarkTimeAPI.convertJodaTime:·gc.alloc.rate                   1024  avgt    5      ≈ 10⁻⁴              MB/sec
BenchmarkTimeAPI.convertJodaTime:·gc.alloc.rate.norm              1024  avgt    5       0.003 ±     0.001    B/op
BenchmarkTimeAPI.convertJodaTime:·gc.count                        1024  avgt    5         ≈ 0              counts

[codecov-commenter]

Codecov Report

Merging #8397 (95369f4) into master (5e7c005) will increase coverage by 33.53%.
The diff coverage is 95.10%.

@@              Coverage Diff              @@
##             master    #8397       +/-   ##
=============================================
+ Coverage     30.54%   64.08%   +33.53%     
- Complexity        0     4275     +4275     
=============================================
  Files          1642     1610       -32     
  Lines         86112    84709     -1403     
  Branches      13000    12853      -147     
=============================================
+ Hits          26304    54285    +27981     
+ Misses        57420    26499    -30921     
- Partials       2388     3925     +1537     

Flag	Coverage Δ
integration1	?
integration2	?
unittests1	67.00% <95.10%> (?)
unittests2	14.13% <0.00%> (?)

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
.../transform/function/DateTimeTransformFunction.java	88.60% <88.60%> (ø)
...e/pinot/common/function/TransformFunctionType.java	100.00% <100.00%> (+15.47%)	⬆️
...r/transform/function/TransformFunctionFactory.java	83.59% <100.00%> (+1.77%)	⬆️
...va/org/apache/pinot/core/routing/RoutingTable.java	0.00% <0.00%> (-100.00%)	⬇️
...va/org/apache/pinot/common/config/NettyConfig.java	0.00% <0.00%> (-100.00%)	⬇️
...a/org/apache/pinot/common/metrics/MinionMeter.java	0.00% <0.00%> (-100.00%)	⬇️
...g/apache/pinot/common/metrics/ControllerMeter.java	0.00% <0.00%> (-100.00%)	⬇️
.../apache/pinot/common/metrics/BrokerQueryPhase.java	0.00% <0.00%> (-100.00%)	⬇️
.../apache/pinot/common/metrics/MinionQueryPhase.java	0.00% <0.00%> (-100.00%)	⬇️
...apache/pinot/common/helix/ExtraInstanceConfig.java	0.00% <0.00%> (-100.00%)	⬇️
... and 1353 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 5e7c005...95369f4. Read the comment docs.