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https://issues.apache.org/jira/browse/OAK-1263?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13938939#comment-13938939
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Thomas Mueller commented on OAK-1263:
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Some formatting changes I did:
* added space before "{" here: "throws Exception {"
* added spaces after commas
* replaced OrderedPropertyIndexEditorProvider.TYPE with OrderedIndex.TYPE
* removed unnecessary ";" at "PropertyValues.newString(value);;"
* some lines were were long (split the lines)
* "private boolean include = false;": removed "= false" as it's the default
* removed unnecessary "()" in "return (xyz)"
* removed newline at "} newline else"
* added missing "{}" at "if (count > max) break;"
* changed "if(paths==null && sortOrder!=null && !sortOrder.isEmpty()){" to
"if (paths == null && sortOrder != null && !sortOrder.isEmpty()) {"
I didn't look at the actual code so far.
> optimize oak index to support 'fast ORDER BY' queries to support sorting &
> pagination for large set of children
> ---------------------------------------------------------------------------------------------------------------
>
> Key: OAK-1263
> URL: https://issues.apache.org/jira/browse/OAK-1263
> Project: Jackrabbit Oak
> Issue Type: Improvement
> Components: query
> Affects Versions: 0.12
> Reporter: Stefan Egli
> Assignee: Thomas Mueller
> Fix For: 0.19
>
> Attachments: OAK-1263-r1.patch, OAK-1263-r1a.patch,
> OAK-1263-r1b.patch, OAK-1263-r1c.patch, OAK-1263-r1d.patch,
> OAK-1263-r2.patch, OAK-1263-r3.patch, OAK-1263-r4.patch, OAK-1263-r5.patch,
> benchmark-20140228112150.log, benchmark-20140228120718.log,
> benchmark-20140228125248.log
>
>
> We have a use case where we'd like to be able to use an index in a
> "pagination-like" fashion. That is, we'd like to be able to have an index on
> a subtree on a certain property, and then run a query which does ORDER BY
> that property combined with OFFSET. That way, essentially allowing pagination
> of child nodes of a particular parent based on 'sorted by a certain property'.
> AFAIU currently the oak index is not optimized to support ORDER BY queries in
> a fast manner. The index keeps 'the child nodes unsorted', ie to process an
> ORDER BY, the child nodes would have to be 'manually sorted' which can result
> in bad performance given a large number of child nodes.
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