[jira] [Resolved] (OAK-2568) Ignore redundant IS NOT NULL constraints

["Chetan Mehrotra (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/OAK-2568?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Chetan Mehrotra resolved OAK-2568.
----------------------------------
    Resolution: Fixed

Fixed in branch with http://svn.apache.org/r1663680

> Ignore redundant IS NOT NULL constraints 
> -----------------------------------------
>
>                 Key: OAK-2568
>                 URL: https://issues.apache.org/jira/browse/OAK-2568
>             Project: Jackrabbit Oak
>          Issue Type: Improvement
>          Components: oak-lucene
>            Reporter: Chetan Mehrotra
>            Assignee: Chetan Mehrotra
>             Fix For: 1.0.12
>
>
> Query like below at times take quite a time to evaluate with LucenePropertyIndex
> {code}
> SELECT * FROM [nt:unstructured] as content WHERE ISDESCENDANTNODE('/content/dam/en/us')
> and(
>     content.[tags] = 'Products:A'
>     or content.[tags] = 'Products:A/B'
>     or content.[tags] = 'Products:A/B'
>     or content.[tags] = 'Products:A'
> )
> and(
>     content.[tags] = 'DocTypes:A'
>     or content.[tags] = 'DocTypes:B'
>     or content.[tags] = 'DocTypes:C'
>     or content.[tags] = 'ProblemType:A'
> )
> and(
>     content.[hasRendition] IS NULL
>     or content.[hasRendition] = 'false'
> )
> {code}
> Now above SQL query translates to following plan
> *Plan on 1.0 branch*
> {noformat}
> [nt:unstructured] as [content] /* lucene:test1(/oak:index/test1) +tags:[* TO *] +(tags:Products:A tags:Products:A/B tags:Products:A/B tags:Products:A) +(tags:DocTypes:A tags:DocTypes:B tags:DocTypes:C tags:ProblemType:A)
>   where ((((isdescendantnode([content], [/content/dam/en/us]))
>   and ([content].[tags] is not null))
>   and ([content].[tags] in(cast('Products:A' as string), cast('Products:A/B' as string), cast('Products:A/B' as string), cast('Products:A' as string))))
>   and ([content].[tags] is not null))
>   and ([content].[tags] in(cast('DocTypes:A' as string), cast('DocTypes:B' as string), cast('DocTypes:C' as string), cast('ProblemType:A' as string))) */
> {noformat}
> Note the extra property restriction of not null which translates in Lucene to {{+tags:\[* TO *\]}}
> *Plan on trunk*
> {noformat}
> [nt:unstructured] as [content] /* lucene:test1(/oak:index/test1) +(tags:Products:A tags:Products:A/B) +(tags:DocTypes:A tags:DocTypes:B tags:DocTypes:C tags:ProblemType:A)
>   where (isdescendantnode([content], [/content/dam/en/us]))
>   and ([content].[tags] in('Products:A', 'Products:A/B'))
>   and ([content].[tags] in('DocTypes:A', 'DocTypes:B', 'DocTypes:C', 'ProblemType:A')) */
> {noformat}
> {color:brown}This one does not have the extra not null constraint{color}
> The query was performing slower on Lucene because the property existence query i.e. not null constraint is currently evaluated as a range query in Lucene which looks like is bit expensive to evaluate. 
> Now as shown above it appears that on trunk the QueryEngine performs such an optimization on its own (possibly done with [1610723|http://svn.apache.org/viewvc/jackrabbit/oak/trunk/oak-core/src/main/java/org/apache/jackrabbit/oak/query/ast/OrImpl.java?r1=1610723&r2=1610722&pathrev=1610723] as part of OAK-1965. This change is not present in branch.
> Given that change in OAK-1965 was quite big it would be better to perform such optimization in {{LucenePropertyIndex}} itself



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