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Posted to issues@hive.apache.org by "Prasanth Jayachandran (JIRA)" <ji...@apache.org> on 2017/11/07 19:33:00 UTC

[jira] [Comment Edited] (HIVE-17417) LazySimple Timestamp is very expensive

    [ https://issues.apache.org/jira/browse/HIVE-17417?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16242708#comment-16242708 ] 

Prasanth Jayachandran edited comment on HIVE-17417 at 11/7/17 7:32 PM:
-----------------------------------------------------------------------

[~ashutoshc] Here is the difference between Joda, JDK8 and SDF

{code}
Benchmark                                                     Mode  Cnt    Score    Error  Units
TimestampFormatBenchmark.benchmarkJDK8TimestampFormatter      avgt   10  274.533 ±  2.663  ns/op
TimestampFormatBenchmark.benchmarkJodaTimeTimestampFormatter  avgt   10  230.096 ±  5.089  ns/op
TimestampFormatBenchmark.benchmarkSimpleDateFormatter         avgt   10  543.846 ± 12.677  ns/op
{code}

On bigger scale this slight difference between joda vs jdk8 will not matter much. Moving to native JDK8 will be better too. Will update the patch with JDK8 formatter.


was (Author: prasanth_j):
[~ashutoshc] Here is the difference between Joda, JDK8 and SDF

{code}
Benchmark                                                     Mode  Cnt    Score    Error  Units
TimestampFormatBenchmark.benchmarkJDK8TimestampFormatter      avgt   10  274.533 ±  2.663  ns/op
TimestampFormatBenchmark.benchmarkJodaTimeTimestampFormatter  avgt   10  230.096 ±  5.089  ns/op
TimestampFormatBenchmark.benchmarkSimpleDateFormatter         avgt   10  543.846 ± 12.677  ns/op
{code}

On bigger scale this slightly difference between joda vs jdk8 will not matter much. Moving to native JDK8 will be better too. Will update the patch with JDK8 formatter.

> LazySimple Timestamp is very expensive
> --------------------------------------
>
>                 Key: HIVE-17417
>                 URL: https://issues.apache.org/jira/browse/HIVE-17417
>             Project: Hive
>          Issue Type: Bug
>          Components: Serializers/Deserializers
>    Affects Versions: 3.0.0, 2.4.0
>            Reporter: Prasanth Jayachandran
>            Assignee: Prasanth Jayachandran
>            Priority: Critical
>         Attachments: HIVE-17417.1.patch, HIVE-17417.2.patch, HIVE-17417.3.patch, HIVE-17417.4.patch, HIVE-17417.5.patch, date-serialize.png, timestamp-serialize.png, ts-jmh-perf.png
>
>
> In a specific case where a schema contains array<struct> with timestamp and date fields (array size >10000). Any access to this column very very expensive in terms of CPU as most of the time is serialization of timestamp and date. Refer attached profiles. >70% time spent in serialization + tostring conversions. 



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