hbase-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Liang Xie (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HBASE-7845) optimize hfile index key
Date Thu, 07 Mar 2013 02:18:13 GMT

    [ https://issues.apache.org/jira/browse/HBASE-7845?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13595445#comment-13595445

Liang Xie commented on HBASE-7845:

Please refer to TestBlocksRead case in v3, it's easy to see the performance gain.
It means after HBASE-4434,HBASE-4433,HBASE-4496,HBASE-4465,HBASE-4585,HBASE-4532, we can optimize
seeking number again, avoid extra potentially disk IO:)

For another expected benefit:  reduce index size,  it depends on the real key characteristic,
if you have a random long key distribution(e.g. md5 hash key) and short value, then the optimization
result will be very outstanding;  and if most of keys are increased sequentially(e.g. key1000,key1001,key1002),then
no obvious index size optimization will be observed.
> optimize hfile index key
> ------------------------
>                 Key: HBASE-7845
>                 URL: https://issues.apache.org/jira/browse/HBASE-7845
>             Project: HBase
>          Issue Type: Improvement
>          Components: HFile
>    Affects Versions: 0.96.0
>            Reporter: Liang Xie
>            Assignee: Liang Xie
>             Fix For: 0.98.0
>         Attachments: HBASE-7845.txt, HBASE-7845-v2.txt, HBASE-7845-v3.txt
> Leveldb uses ByteWiseComparatorImpl::FindShortestSeparator() & FindShortSuccessor()
to reduce index key size, it would be helpful under special conditions.

This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira

View raw message