[
https://issues.apache.org/jira/browse/OAK-8002?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16752293#comment-16752293
]
Julian Reschke commented on OAK-8002:
-------------------------------------
trunk: [r1852135|http://svn.apache.org/r1852135]
> RDBDocumentStore: add RDB-specific MissingLastRevSeeker
> --------------------------------------------------------
>
> Key: OAK-8002
> URL: https://issues.apache.org/jira/browse/OAK-8002
> Project: Jackrabbit Oak
> Issue Type: Technical task
> Components: rdbmk
> Reporter: Julian Reschke
> Assignee: Julian Reschke
> Priority: Minor
> Labels: candidate_oak_1_10
> Fix For: 1.12, 1.11.0
>
> Attachments: OAK-8002.diff
>
>
> {{MissingLastRevSeeker}} is slow on DB2. This is because the generic
> {{MissingLastRevSeeker}} gets candidate in batches (of 100), but in order to
> do batching, requires results to be sorted by ID.
> For DB2 we by default have indices on both ID and MODIFIED, but contrary to
> our expection a query that involves both indices does not perforn well.
> Adding a compound index on ID *and* MODIFIED improves performance, but I'm
> hesitant to add this just to improve a recovery job.
> A more logical approach would be not to require batching/sorting by adopting
> the approach in {{MongoMissingLastRevSeeker}} which doesn't require sorting
> by ID in the first place.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
