[
https://issues.apache.org/jira/browse/HAWQ-975?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15451831#comment-15451831
]
Chunling Wang commented on HAWQ-975:
------------------------------------
It is because that the VDSO on agents of AWS does not work well. So the
execution time of function 'gettimeofday()' is too much.
> Queries run much slower with 'explain analyze' than which without 'explain
> analyze'
> ------------------------------------------------------------------------------------
>
> Key: HAWQ-975
> URL: https://issues.apache.org/jira/browse/HAWQ-975
> Project: Apache HAWQ
> Issue Type: Bug
> Components: Core
> Reporter: Chunling Wang
> Assignee: Lei Chang
> Priority: Critical
> Labels: performance
> Fix For: 2.0.1.0-incubating
>
>
> When we run queries with 'explain analyze' in AWS cluster, the total running
> time is about 2-3 times longer than which without 'explain analyze'.
> Here is a group of TPC-H results for queries with 'explain analyze' and
> queries without 'explain analyze'.
> ||query ||without 'explain analyze' ||with 'explain analyze'
> ||multiple
> |TPCH_Query_01 | 311843 | 818658 | 2.63
> |TPCH_Query_02 | 34675 | 117884 | 3.40
> |TPCH_Query_03 | 166155 | 422131 | 2.54
> |TPCH_Query_04 | 157807 | 507143 | 3.21
> |TPCH_Query_05 | 272657 | 710573 | 2.61
> |TPCH_Query_06 | 12508 | 22276 | 1.78
> |TPCH_Query_07 | 71893 | 370338 | 5.15
> |TPCH_Query_08 | 129999 | 672625 | 5.17
> |TPCH_Query_09 | 575709 | 1171672 | 2.04
> |TPCH_Query_10 | 93770 | 233391 | 2.49
> |TPCH_Query_11 | 16252 | 58360 | 3.59
> |TPCH_Query_12 | 142576 | 237270 | 1.66
> |TPCH_Query_13 | 72682 | 343257 | 4.72
> |TPCH_Query_14 | 10410 | 32337 | 3.11
> |TPCH_Query_15 | 25719 | 98705 | 3.84
> |TPCH_Query_16 | 21382 | 76877 | 3.60
> |TPCH_Query_17 | 839683 | 2041169 | 2.43
> |TPCH_Query_18 | 460570 | 1065940 | 2.31
> |TPCH_Query_19 | 69075 | 82286 | 1.19
> |TPCH_Query_20 | 78263 | 292041 | 3.73
> |TPCH_Query_21 | 505606 | 1549690 | 3.07
> |TPCH_Query_22 | 56450 | 329837 | 5.84
> |Total | 4125684 | 11254460 |
> 2.73
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
