You are viewing a plain text version of this content. The canonical link for it is here.

Posted to oak-issues@jackrabbit.apache.org by "Thomas Mueller (JIRA)" <ji...@apache.org> on 2014/08/11 15:07:11 UTC

[jira] [Created] (OAK-2023) Optimal index usage for XPath queries with "order by" combined with "or"

Thomas Mueller created OAK-2023:
-----------------------------------

             Summary: Optimal index usage for XPath queries with "order by" combined with "or"
                 Key: OAK-2023
                 URL: https://issues.apache.org/jira/browse/OAK-2023
             Project: Jackrabbit Oak
          Issue Type: Improvement
          Components: query
            Reporter: Thomas Mueller
            Assignee: Thomas Mueller
             Fix For: 1.1


XPath queries with "or" are converted to union, even if there is an "order by" clause. In such cases, sorting is done in memory. See also OAK-2022.

For some queries, it might be better to not use union, but use an ordered index instead. This is tricky to decide up-front, but it would be possible to estimate the cost of both variants and pick the one that seems better.



--
This message was sent by Atlassian JIRA
(v6.2#6252)