[
https://issues.apache.org/jira/browse/HIVE-16151?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15957494#comment-15957494
]
Gopal V edited comment on HIVE-16151 at 4/5/17 7:25 PM:
--------------------------------------------------------
This came up as a ~4% performance loss in an extra null check, but does allow
for larger hash tables.
LGTM - +1.
was (Author: gopalv):
This came up as a ~4% performance in an extra null check, but does allow for
larger hash tables.
LGTM - +1.
> BytesBytesHashTable allocates large arrays
> ------------------------------------------
>
> Key: HIVE-16151
> URL: https://issues.apache.org/jira/browse/HIVE-16151
> Project: Hive
> Issue Type: Bug
> Reporter: Prasanth Jayachandran
> Assignee: Sergey Shelukhin
> Attachments: HIVE-16151.patch
>
>
> These arrays cause GC pressure and also impose key count limitations on the
> table. Wrt the latter, we won't be able to get rid of it without a 64-bit
> hash function, but for now we can get rid of the former. If we need the
> latter we'd add murmur64 and probably account for it differently for resize
> (we don't want to blow up the hashtable by 4 bytes/key in the common case
> where #of keys is less than ~1.5B :))
--
This message was sent by Atlassian JIRA
(v6.3.15#6346)
