[
https://issues.apache.org/jira/browse/CASSANDRA-4131?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13738387#comment-13738387
]
Cyril Scetbon edited comment on CASSANDRA-4131 at 8/14/13 9:39 AM:
-------------------------------------------------------------------
I've met a performance issue where there is a few data. In my example, I have
only a few rows :
{code}cqlsh>select count(*) from light_column;
count
-------
4
{code}
It takes less than a second with cqlsh whereas it takes near 600 seconds with
Hive. Please see logs at http://pastebin.com/ippy96GY
There are 257 mappers (to scan data from 256 vnodes) and they took a lot of CPU
even if the process says at the end :
*Total MapReduce CPU Time Spent: 0 msec*
Another issue is that the count number is false as it returns 5 instead of 4,
and it's caused by a deleted row counted as alive !
was (Author: cscetbon):
I've met a performance issue where there is a few data. In my example, I
have only a few rows :
{code}cqlsh>select count(*) from light_column;
count
-------
4
{code}
It takes less than a second with cqlsh whereas it takes near 600 seconds with
Hive. Please see logs at http://pastebin.com/ippy96GY
There are 257 mappers (to scan data from 256 vnodes) and they took a lot of CPU
even if the process says at the end :
*Total MapReduce CPU Time Spent: 0 msec*
Another issue is that the count number is false as it returns 5 instead of 4.
> Integrate Hive support to be in core cassandra
> ----------------------------------------------
>
> Key: CASSANDRA-4131
> URL: https://issues.apache.org/jira/browse/CASSANDRA-4131
> Project: Cassandra
> Issue Type: Improvement
> Reporter: Jeremy Hanna
> Assignee: Edward Capriolo
> Labels: hadoop, hive
>
> The standalone hive support (at https://github.com/riptano/hive) would be
> great to have in-tree so that people don't have to go out to github to
> download it and wonder if it's a left-for-dead external shim.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira
