jackrabbit-oak-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Thomas Mueller (JIRA)" <j...@apache.org>
Subject [jira] [Created] (OAK-2023) Optimal index usage for XPath queries with "order by" combined with "or"
Date Mon, 11 Aug 2014 13:07:11 GMT
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)

Mime
View raw message