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Posted to derby-dev@db.apache.org by "Tony Brusseau (JIRA)" <ji...@apache.org> on 2010/05/07 19:25:49 UTC
[jira] Issue Comment Edited: (DERBY-4422) Extremely slow subqueries
when subquerying on strings
[ https://issues.apache.org/jira/browse/DERBY-4422?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12865243#action_12865243 ]
Tony Brusseau edited comment on DERBY-4422 at 5/7/10 1:24 PM:
--------------------------------------------------------------
I've discovered another somewhat strange performance issue with a related query where having more than one string in an "IN" clause causes orders of magnitude slow down:
SELECT DISTINCT C.EXTERNAL_ID, C.OWL_NL_ID, CYCL, C.PREFERRED_NL, C.PREFERRED_NL_SORTABLE, C.COMMENT, C.CONCEPT_TYPE, CS.NL, CS.STRING_TYPE, C.INTERNAL_ID FROM OC_CONCEPTS C, OC_CONCEPT_STRINGS CS, (SELECT DISTINCT INTERNAL_ID
FROM OC_CONCEPTS WHERE EXTERNAL_ID IN (
'Mw2CHiu-uEr4nCkRsZ2tw3ljb3JwDYMeK71Y5HacKRGxna3DeWNvcnAeK71YxJScKRGxna3DeWNvcnAeK71Y0qCcKRGxna3DeWNvcnA'
)) X
WHERE (C.INTERNAL_ID = X.INTERNAL_ID) AND (C.INTERNAL_ID = CS.CONCEPT_ID)
ORDER BY C.PREFERRED_NL_SORTABLE, C.INTERNAL_ID, CS.STRING_TYPE
==> Execution finished after 0.003 s, 0 error(s) occurred.
SELECT DISTINCT C.EXTERNAL_ID, C.OWL_NL_ID, CYCL, C.PREFERRED_NL, C.PREFERRED_NL_SORTABLE, C.COMMENT, C.CONCEPT_TYPE, CS.NL, CS.STRING_TYPE, C.INTERNAL_ID FROM OC_CONCEPTS C, OC_CONCEPT_STRINGS CS, (SELECT DISTINCT INTERNAL_ID
FROM OC_CONCEPTS WHERE EXTERNAL_ID IN (
'Mw2CHiu-uEr4nCkRsZ2tw3ljb3JwDYMeK71Y5HacKRGxna3DeWNvcnAeK71Y6VGcKRGxna3DeWNvcnAeK71Y7BKcKRGxna3DeWNvcnA'
)) X
WHERE (C.INTERNAL_ID = X.INTERNAL_ID) AND (C.INTERNAL_ID = CS.CONCEPT_ID)
ORDER BY C.PREFERRED_NL_SORTABLE, C.INTERNAL_ID, CS.STRING_TYPE
==> Execution finished after 0.003 s, 0 error(s) occurred.
SELECT DISTINCT C.EXTERNAL_ID, C.OWL_NL_ID, CYCL, C.PREFERRED_NL, C.PREFERRED_NL_SORTABLE, C.COMMENT, C.CONCEPT_TYPE, CS.NL, CS.STRING_TYPE, C.INTERNAL_ID FROM OC_CONCEPTS C, OC_CONCEPT_STRINGS CS, (SELECT DISTINCT INTERNAL_ID
FROM OC_CONCEPTS WHERE EXTERNAL_ID IN (
'Mw2CHiu-uEr4nCkRsZ2tw3ljb3JwDYMeK71Y5HacKRGxna3DeWNvcnAeK71YxJScKRGxna3DeWNvcnAeK71Y0qCcKRGxna3DeWNvcnA',
'Mw2CHiu-uEr4nCkRsZ2tw3ljb3JwDYMeK71Y5HacKRGxna3DeWNvcnAeK71Y6VGcKRGxna3DeWNvcnAeK71Y7BKcKRGxna3DeWNvcnA'
)) X
WHERE (C.INTERNAL_ID = X.INTERNAL_ID) AND (C.INTERNAL_ID = CS.CONCEPT_ID)
ORDER BY C.PREFERRED_NL_SORTABLE, C.INTERNAL_ID, CS.STRING_TYPE
==> Execution finished after 2.37 s, 0 error(s) occurred.
was (Author: apb):
I've discovered another somewhat strange performance issue with a related query where having more than one string in an "IN" clause causes orders of magnitude slow down):
SELECT DISTINCT C.EXTERNAL_ID, C.OWL_NL_ID, CYCL, C.PREFERRED_NL, C.PREFERRED_NL_SORTABLE, C.COMMENT, C.CONCEPT_TYPE, CS.NL, CS.STRING_TYPE, C.INTERNAL_ID FROM OC_CONCEPTS C, OC_CONCEPT_STRINGS CS, (SELECT DISTINCT INTERNAL_ID
FROM OC_CONCEPTS WHERE EXTERNAL_ID IN (
'Mw2CHiu-uEr4nCkRsZ2tw3ljb3JwDYMeK71Y5HacKRGxna3DeWNvcnAeK71YxJScKRGxna3DeWNvcnAeK71Y0qCcKRGxna3DeWNvcnA'
)) X
WHERE (C.INTERNAL_ID = X.INTERNAL_ID) AND (C.INTERNAL_ID = CS.CONCEPT_ID)
ORDER BY C.PREFERRED_NL_SORTABLE, C.INTERNAL_ID, CS.STRING_TYPE
==> Execution finished after 0.003 s, 0 error(s) occurred.
SELECT DISTINCT C.EXTERNAL_ID, C.OWL_NL_ID, CYCL, C.PREFERRED_NL, C.PREFERRED_NL_SORTABLE, C.COMMENT, C.CONCEPT_TYPE, CS.NL, CS.STRING_TYPE, C.INTERNAL_ID FROM OC_CONCEPTS C, OC_CONCEPT_STRINGS CS, (SELECT DISTINCT INTERNAL_ID
FROM OC_CONCEPTS WHERE EXTERNAL_ID IN (
'Mw2CHiu-uEr4nCkRsZ2tw3ljb3JwDYMeK71Y5HacKRGxna3DeWNvcnAeK71Y6VGcKRGxna3DeWNvcnAeK71Y7BKcKRGxna3DeWNvcnA'
)) X
WHERE (C.INTERNAL_ID = X.INTERNAL_ID) AND (C.INTERNAL_ID = CS.CONCEPT_ID)
ORDER BY C.PREFERRED_NL_SORTABLE, C.INTERNAL_ID, CS.STRING_TYPE
==> Execution finished after 0.003 s, 0 error(s) occurred.
SELECT DISTINCT C.EXTERNAL_ID, C.OWL_NL_ID, CYCL, C.PREFERRED_NL, C.PREFERRED_NL_SORTABLE, C.COMMENT, C.CONCEPT_TYPE, CS.NL, CS.STRING_TYPE, C.INTERNAL_ID FROM OC_CONCEPTS C, OC_CONCEPT_STRINGS CS, (SELECT DISTINCT INTERNAL_ID
FROM OC_CONCEPTS WHERE EXTERNAL_ID IN (
'Mw2CHiu-uEr4nCkRsZ2tw3ljb3JwDYMeK71Y5HacKRGxna3DeWNvcnAeK71YxJScKRGxna3DeWNvcnAeK71Y0qCcKRGxna3DeWNvcnA',
'Mw2CHiu-uEr4nCkRsZ2tw3ljb3JwDYMeK71Y5HacKRGxna3DeWNvcnAeK71Y6VGcKRGxna3DeWNvcnAeK71Y7BKcKRGxna3DeWNvcnA'
)) X
WHERE (C.INTERNAL_ID = X.INTERNAL_ID) AND (C.INTERNAL_ID = CS.CONCEPT_ID)
ORDER BY C.PREFERRED_NL_SORTABLE, C.INTERNAL_ID, CS.STRING_TYPE
==> Execution finished after 2.37 s, 0 error(s) occurred.
> Extremely slow subqueries when subquerying on strings
> -----------------------------------------------------
>
> Key: DERBY-4422
> URL: https://issues.apache.org/jira/browse/DERBY-4422
> Project: Derby
> Issue Type: Bug
> Affects Versions: 10.5.3.0
> Environment: Suse Unix 10.3.
> Reporter: Tony Brusseau
> Attachments: badqp.txt, derby.log, fixed-time-derby.log, goodqp.txt, SQLFile1.sqlaa.gz, SQLFile1.sqlab.gz, SQLFile2.sqlaa.gz, SQLFile2.sqlab.gz, SQLFile2.sqlac.gz, tmp2.sql, unlimited-time-derby.log
>
>
> SELECT DISTINCT C.INTERNAL_ID
> FROM OC_CONCEPTS C
> WHERE
> (C.INTERNAL_ID IN (SELECT DISTINCT OCS.CONCEPT_ID FROM OC_CONCEPT_STRINGS OCS WHERE OCS.CONCEPT_ID=1))
> Both queries above are trivial and they are both acting on fully indexed primary key columns. This query runs just fine.
> However, when I make the small modification of searching on an indexed text column in the sub query, it takes over 6 seconds to run, even though both queries independently take < 1ms run.
> SELECT DISTINCT C.INTERNAL_ID
> FROM OC_CONCEPTS C
> WHERE
> (C.INTERNAL_ID IN (SELECT DISTINCT OCS.CONCEPT_ID FROM OC_CONCEPT_STRINGS OCS WHERE OCS.NL_LC = 'dash'))
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