[
https://issues.apache.org/jira/browse/OAK-1263?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13922297#comment-13922297
]
Alex Parvulescu commented on OAK-1263:
--------------------------------------
If I'm not mistaken the #cost method is not implemented yet (it is inherited
from the default property index impl), so this index can be picked up in its
unfinished form by the query engine, depending on which comes first in the list
of available indexes.
I suggest adding an infinite cost to the index until everything else is cleared
out.
> 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,
> 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.
--
This message was sent by Atlassian JIRA
(v6.2#6252)
