[
https://issues.apache.org/jira/browse/HIVE-24746?focusedWorklogId=550181&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-550181
]
ASF GitHub Bot logged work on HIVE-24746:
-----------------------------------------
Author: ASF GitHub Bot
Created on: 09/Feb/21 10:58
Start Date: 09/Feb/21 10:58
Worklog Time Spent: 10m
Work Description: abstractdog edited a comment on pull request #1950:
URL: https://github.com/apache/hive/pull/1950#issuecomment-775826706
> Hey @abstractdog change makes sense to me -- question is how often do we
really call the TsBoundary Scanner during range computation? Is the test
representative of the scanario?
>
> Would the optimization make sense to other types as well e.g.,
TimestampLocalTZ or Date?
this could be heavy code path yes, as in case range based windows, every row
needs to be checked:
```
at
org.apache.hadoop.hive.common.type.Timestamp.setTimeInSeconds(Timestamp.java:133)
at
org.apache.hadoop.hive.serde2.io.TimestampWritableV2.populateTimestamp(TimestampWritableV2.java:401)
at
org.apache.hadoop.hive.serde2.io.TimestampWritableV2.getTimestamp(TimestampWritableV2.java:210)
at
org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorUtils.getTimestamp(PrimitiveObjectInspectorUtils.java:1239)
at
org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorUtils.getTimestamp(PrimitiveObjectInspectorUtils.java:1181)
at
org.apache.hadoop.hive.ql.udf.ptf.TimestampValueBoundaryScanner.isEqual(ValueBoundaryScanner.java:848)
at
org.apache.hadoop.hive.ql.udf.ptf.SingleValueBoundaryScanner.computeEndCurrentRow(ValueBoundaryScanner.java:593)
at
org.apache.hadoop.hive.ql.udf.ptf.SingleValueBoundaryScanner.computeEnd(ValueBoundaryScanner.java:530)
at
org.apache.hadoop.hive.ql.udf.ptf.BasePartitionEvaluator.getRange(BasePartitionEvaluator.java:273)
at
org.apache.hadoop.hive.ql.udf.ptf.BasePartitionEvaluator.iterate(BasePartitionEvaluator.java:219)
at
org.apache.hadoop.hive.ql.udf.ptf.WindowingTableFunction.evaluateWindowFunction(WindowingTableFunction.java:147)
at
org.apache.hadoop.hive.ql.udf.ptf.WindowingTableFunction.access$100(WindowingTableFunction.java:61)
at
org.apache.hadoop.hive.ql.udf.ptf.WindowingTableFunction$WindowingIterator.next(WindowingTableFunction.java:755)
at
org.apache.hadoop.hive.ql.exec.PTFOperator$PTFInvocation.finishPartition(PTFOperator.java:373)
at
org.apache.hadoop.hive.ql.exec.PTFOperator.closeOp(PTFOperator.java:104)
at org.apache.hadoop.hive.ql.exec.Operator.close(Operator.java:732)
at org.apache.hadoop.hive.ql.exec.Operator.close(Operator.java:756)
at
org.apache.hadoop.hive.ql.exec.tez.ReduceRecordProcessor.close(ReduceRecordProcessor.java:383)
at
org.apache.hadoop.hive.ql.exec.tez.TezProcessor.initializeAndRunProcessor(TezProcessor.java:284)
at
org.apache.hadoop.hive.ql.exec.tez.TezProcessor.run(TezProcessor.java:250)
```
looks like a good idea to check other types' compareTo shortcuts
TimestampLocalTZWritable doesn't seem to be subject to the same optimization
as its compareTo will do heavy operations anyway (getTimestampTZ ->
populateTimestampTZ)
```
@Override
public int compareTo(TimestampLocalTZWritable o) {
return getTimestampTZ().compareTo(o.getTimestampTZ());
}
```
we'll have to find out if this can be simplified in the same way (maybe
another jira, fyi: @rbalamohan if you're aware of this), so compareTo should
use bytes if bytes are present, similarly to TimestampWritableV2:
```
public int compareTo(TimestampWritableV2 t) {
checkBytes();
long s1 = this.getSeconds();
...
```
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Issue Time Tracking
-------------------
Worklog Id: (was: 550181)
Time Spent: 1h 40m (was: 1.5h)
> PTF: TimestampValueBoundaryScanner can be optimised during range computation
> ----------------------------------------------------------------------------
>
> Key: HIVE-24746
> URL: https://issues.apache.org/jira/browse/HIVE-24746
> Project: Hive
> Issue Type: Improvement
> Reporter: László Bodor
> Assignee: László Bodor
> Priority: Major
> Labels: pull-request-available
> Time Spent: 1h 40m
> Remaining Estimate: 0h
>
> During range computation, timestamp ranges become a hotspot due to
> "TimeStamp" comparisons. It has to construct the entire TimeStamp object via
> OI (which incurs LocalTime computation etc internally).
>
> All these are done for "equals" comparison which can be done with "seconds &
> nanoseconds" present in TimeStamp.
>
> [https://github.com/apache/hive/blob/master/ql/src/java/org/apache/hadoop/hive/ql/udf/ptf/ValueBoundaryScanner.java#L852]
>
>
> Request is to explore optimising this code path, so that equals() can be
> performed with "seconds/nanoseconds" instead of entire timestamp
>
> {noformat}
> at
> org.apache.hadoop.hive.common.type.Timestamp.setTimeInSeconds(Timestamp.java:133)
> at
> org.apache.hadoop.hive.serde2.io.TimestampWritableV2.populateTimestamp(TimestampWritableV2.java:401)
> at
> org.apache.hadoop.hive.serde2.io.TimestampWritableV2.getTimestamp(TimestampWritableV2.java:210)
> at
> org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorUtils.getTimestamp(PrimitiveObjectInspectorUtils.java:1239)
> at
> org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorUtils.getTimestamp(PrimitiveObjectInspectorUtils.java:1181)
> at
> org.apache.hadoop.hive.ql.udf.ptf.TimestampValueBoundaryScanner.isEqual(ValueBoundaryScanner.java:848)
> at
> org.apache.hadoop.hive.ql.udf.ptf.SingleValueBoundaryScanner.computeEndCurrentRow(ValueBoundaryScanner.java:593)
> at
> org.apache.hadoop.hive.ql.udf.ptf.SingleValueBoundaryScanner.computeEnd(ValueBoundaryScanner.java:530)
> at
> org.apache.hadoop.hive.ql.udf.ptf.BasePartitionEvaluator.getRange(BasePartitionEvaluator.java:273)
> at
> org.apache.hadoop.hive.ql.udf.ptf.BasePartitionEvaluator.iterate(BasePartitionEvaluator.java:219)
> at
> org.apache.hadoop.hive.ql.udf.ptf.WindowingTableFunction.evaluateWindowFunction(WindowingTableFunction.java:147)
> at
> org.apache.hadoop.hive.ql.udf.ptf.WindowingTableFunction.access$100(WindowingTableFunction.java:61)
> at
> org.apache.hadoop.hive.ql.udf.ptf.WindowingTableFunction$WindowingIterator.next(WindowingTableFunction.java:755)
> at
> org.apache.hadoop.hive.ql.exec.PTFOperator$PTFInvocation.finishPartition(PTFOperator.java:373)
> at
> org.apache.hadoop.hive.ql.exec.PTFOperator.closeOp(PTFOperator.java:104)
> at org.apache.hadoop.hive.ql.exec.Operator.close(Operator.java:732)
> at org.apache.hadoop.hive.ql.exec.Operator.close(Operator.java:756)
> at
> org.apache.hadoop.hive.ql.exec.tez.ReduceRecordProcessor.close(ReduceRecordProcessor.java:383)
> at
> org.apache.hadoop.hive.ql.exec.tez.TezProcessor.initializeAndRunProcessor(TezProcessor.java:284)
> at
> org.apache.hadoop.hive.ql.exec.tez.TezProcessor.run(TezProcessor.java:250)
> {noformat}
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