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Posted to dev@phoenix.apache.org by "James Taylor (JIRA)" <ji...@apache.org> on 2016/05/26 20:54:13 UTC
[jira] [Commented] (PHOENIX-2943) Performance of parallel order by
query is > 30X slower than serial execution
[ https://issues.apache.org/jira/browse/PHOENIX-2943?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15302903#comment-15302903 ]
James Taylor commented on PHOENIX-2943:
---------------------------------------
Is this a regression from 4.7.0, [~mujtabachohan]?
> Performance of parallel order by query is > 30X slower than serial execution
> ----------------------------------------------------------------------------
>
> Key: PHOENIX-2943
> URL: https://issues.apache.org/jira/browse/PHOENIX-2943
> Project: Phoenix
> Issue Type: Bug
> Reporter: Mujtaba Chohan
> Fix For: 4.8.0
>
>
> {code}
> select /*+SERIAL*/ L_DISCOUNT, L_QUANTITY from lineitem_encoded order by (l_discount,L_QUANTITY) limit 1;
> +-------------+-------------+
> | L_DISCOUNT | L_QUANTITY |
> +-------------+-------------+
> | 0.04 | 17 |
> +-------------+-------------+
> 1 row selected (0.129 seconds)
> select L_DISCOUNT, L_QUANTITY from lineitem_encoded order by (l_discount,L_QUANTITY) limit 1;
> +-------------+-------------+
> | L_DISCOUNT | L_QUANTITY |
> +-------------+-------------+
> | 0.04 | 17 |
> +-------------+-------------+
> 1 row selected (4.63 seconds)
> explain select /*+SERIAL*/ L_DISCOUNT, L_QUANTITY from lineitem_encoded order by (l_discount,L_QUANTITY) limit 1;
> +------------------------------------------------------------------------------------------------+
> | PLAN |
> +------------------------------------------------------------------------------------------------+
> | CLIENT 417-CHUNK 5978838 ROWS 4150009682 BYTES SERIAL 417-WAY FULL SCAN OVER LINEITEM_ENCODED |
> | SERVER TOP 1 ROW SORTED BY [(L_DISCOUNT, L_QUANTITY)] |
> | CLIENT MERGE SORT |
> +------------------------------------------------------------------------------------------------+
> 3 rows selected (0.016 seconds)
> 0: jdbc:phoenix:localhost> explain select L_DISCOUNT, L_QUANTITY from lineitem_encoded order by (l_discount,L_QUANTITY) limit 1;
> +--------------------------------------------------------------------------------------------------+
> | PLAN |
> +--------------------------------------------------------------------------------------------------+
> | CLIENT 417-CHUNK 5978838 ROWS 4150009682 BYTES PARALLEL 417-WAY FULL SCAN OVER LINEITEM_ENCODED |
> | SERVER TOP 1 ROW SORTED BY [(L_DISCOUNT, L_QUANTITY)] |
> | CLIENT MERGE SORT |
> +--------------------------------------------------------------------------------------------------+
> 3 rows selected (0.015 seconds)
> {code}
> Profiler information on this to be added soon.
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