[
https://issues.apache.org/jira/browse/HIVE-4160?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Jitendra Nath Pandey updated HIVE-4160:
---------------------------------------
Description:
Hive query execution engine currently processes one row at a time. A single
row of data goes through all the operators before next row can be processed.
This mode of processing is very inefficient in terms of CPU usage. Research has
demonstrated that this yields very low instructions per cycle [MonetDB]. Also
currently hive heavily relies on lazy deserialization and data columns go
through a layer of object inspectors that identify column type, de-serialize
data and determine appropriate expression routines in the inner loop. These
layers of virtual method calls further slow down the processing.
was:
Hive query execution engine currently processes one row at a time. A single
row of data goes through all the operators before next row can be processed.
This mode of processing is very inefficient in terms of CPU usage. Research has
demonstrated that this yields very low instructions per cycle [MonetDB]. Also
currently hive heavily relies on lazy deserialization and data columns go
through a layer of object inspectors that identify column type, de-serialize
data and determine appropriate expression routines in the inner loop. These
layers of virtual method calls further slow down the processing.
Reference: http://www-db.cs.wisc.edu/cidr/cidr2005/papers/P19.pdf
> Vectorized Query Execution in Hive
> ----------------------------------
>
> Key: HIVE-4160
> URL: https://issues.apache.org/jira/browse/HIVE-4160
> Project: Hive
> Issue Type: New Feature
> Reporter: Jitendra Nath Pandey
> Assignee: Jitendra Nath Pandey
>
> Hive query execution engine currently processes one row at a time. A single
> row of data goes through all the operators before next row can be processed.
> This mode of processing is very inefficient in terms of CPU usage. Research
> has demonstrated that this yields very low instructions per cycle [MonetDB].
> Also currently hive heavily relies on lazy deserialization and data columns
> go through a layer of object inspectors that identify column type,
> de-serialize data and determine appropriate expression routines in the inner
> loop. These layers of virtual method calls further slow down the processing.
--
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
