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Posted to issues@hive.apache.org by "Greg Senia (Jira)" <ji...@apache.org> on 2019/10/29 01:14:00 UTC
[jira] [Commented] (HIVE-18624) Parsing time is extremely high (~10
min) for queries with complex select expressions
[ https://issues.apache.org/jira/browse/HIVE-18624?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16961586#comment-16961586 ]
Greg Senia commented on HIVE-18624:
-----------------------------------
Re-created this problem with a simple query as:
Query:: select (((((((((((((((((((((((((((((((((((((((((((((((((((((((('x')))))))))))))))))))))))))))))))))))))))))))))))))))))))) from processed_opendata_samples.nyse_stocks limit 2
> Parsing time is extremely high (~10 min) for queries with complex select expressions
> ------------------------------------------------------------------------------------
>
> Key: HIVE-18624
> URL: https://issues.apache.org/jira/browse/HIVE-18624
> Project: Hive
> Issue Type: Bug
> Components: Hive, Parser
> Affects Versions: 2.0.0, 3.0.0, 2.3.2
> Reporter: Amruth Sampath
> Assignee: Zoltan Haindrich
> Priority: Major
> Fix For: 2.4.0, 4.0.0, 3.2.0, 3.1.2
>
> Attachments: HIVE-18624.01.patch, HIVE-18624.02.patch, thread_dump
>
>
> Explain of the same query takes
> 0.1 to 3 seconds in hive 2.1.0 &
> 10-15 min in hive 2.3.2 & latest master
> Sample expression below
> {code:java}
> EXPLAIN
> SELECT DISTINCT
> IF(lower('a') <= lower('a')
> ,'a'
> ,IF(('a' IS NULL AND from_unixtime(UNIX_TIMESTAMP()) <= 'a')
> ,'a'
> ,IF(if('a' = 'a', TRUE, FALSE) = 1
> ,'a'
> ,IF(('a' = 1 and lower('a') NOT IN ('a', 'a')
> and lower(if('a' = 'a','a','a')) <= lower('a'))
> OR ('a' like 'a' OR 'a' like 'a')
> OR 'a' in ('a','a')
> ,'a'
> ,IF(if(lower('a') in ('a', 'a') and 'a'='a', TRUE, FALSE) = 1
> ,'a'
> ,IF('a'='a' and unix_timestamp(if('a' = 'a',cast('a' as string),coalesce('a',cast('a' as string),from_unixtime(unix_timestamp())))) <= unix_timestamp(concat_ws('a',cast(lower('a') as string),'00:00:00')) + 9*3600
> ,'a'
> ,If(lower('a') <= lower('a')
> and if(lower('a') in ('a', 'a') and 'a'<>'a', TRUE, FALSE) <> 1
> ,'a'
> ,IF('a'=1 AND 'a'=1
> ,'a'
> ,IF('a' = 1 and COALESCE(cast('a' as int),0) = 0
> ,'a'
> ,IF('a' = 'a'
> ,'a'
> ,If('a' = 'a' AND lower('a')>lower(if(lower('a')<1830,'a',cast(date_add('a',1) as timestamp)))
> ,'a'
> ,IF('a' = 1
> ,IF('a' in ('a', 'a') and ((unix_timestamp('a')-unix_timestamp('a')) / 60) > 30 and 'a' = 1
> ,'a', 'a')
> ,IF(if('a' = 'a', FALSE, TRUE ) = 1 AND 'a' IS NULL
> ,'a'
> ,IF('a' = 1 and 'a'>0
> , 'a'
> ,IF('a' = 1 AND 'a' ='a'
> ,'a'
> ,IF('a' is not null and 'a' is not null and 'a' > 'a'
> ,'a'
> ,IF('a' = 1
> ,'a'
> ,IF('a' = 'a'
> ,'a'
> ,If('a' = 1
> ,'a'
> ,IF('a' = 1
> ,'a'
> ,IF('a' = 1
> ,'a'
> ,IF('a' ='a' and 'a' ='a' and cast(unix_timestamp('a') as int) + 93600 < cast(unix_timestamp() as int)
> ,'a'
> ,IF('a' = 'a'
> ,'a'
> ,IF('a' = 'a' and 'a' in ('a','a','a')
> ,'a'
> ,IF('a' = 'a'
> ,'a','a'))
> )))))))))))))))))))))))
> AS test_comp_exp
> {code}
>
> Taking a look at [^thread_dump] shows a very large function stack getting created.
> Reverting HIVE-15578 (92f31d07aa988d4a460aac56e369bfa386361776) seem to speed up the parsing.
>
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