[
https://issues.apache.org/jira/browse/HIVE-17243?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Prasanth Jayachandran resolved HIVE-17243.
------------------------------------------
Resolution: Won't Fix
> Replace Hive's JavaDataModel with Java Object Layout
> ----------------------------------------------------
>
> Key: HIVE-17243
> URL: https://issues.apache.org/jira/browse/HIVE-17243
> Project: Hive
> Issue Type: Improvement
> Affects Versions: 3.0.0
> Reporter: Prasanth Jayachandran
> Assignee: Prasanth Jayachandran
>
> org.apache.hadoop.hive.ql.util.JavaDataModel is used for estimating memory of
> objects in many places. The problem with this approach is that manual
> accounting for all fields and references has to be done. This will also be
> problematic for cases where shallow object size vs deep object sizes are
> required.
> Hash table memory monitoring does accounting for size of the hash tables. The
> estimated sizes of hash tables are often very different for non-vector
> operators whereas the estimates are close to actual object size for
> vectorized operators. Also addition of fields requires manual changes to
> memory monitoring.
> Java object layout is openjdk project that can provide shallow and deep
> object sizes without using java agents. We can leverage that for much more
> accurate memory estimates.
--
This message was sent by Atlassian JIRA
(v6.4.14#64029)
