accumulo-notifications mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Drew Farris (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (ACCUMULO-803) Add Reverse Logical Time as a Time Type
Date Sat, 27 Oct 2012 02:03:12 GMT

    [ https://issues.apache.org/jira/browse/ACCUMULO-803?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13485329#comment-13485329
] 

Drew Farris commented on ACCUMULO-803:
--------------------------------------

I feel that reversing the assignment of timestamps is the safest approach. The alternative
would involve modifying the code that sorts entries in rfiles which I am a little reluctant
to touch at this point. I don't know that there's an alternative that would be less invasive
than reverse logical time.
                
> Add Reverse Logical Time as a Time Type
> ---------------------------------------
>
>                 Key: ACCUMULO-803
>                 URL: https://issues.apache.org/jira/browse/ACCUMULO-803
>             Project: Accumulo
>          Issue Type: Improvement
>          Components: tserver
>    Affects Versions: 1.5.0
>            Reporter: Drew Farris
>            Assignee: Drew Farris
>            Priority: Minor
>         Attachments: ACCUMULO-803.patch, ACCUMULO-803.patch
>
>
> In a context where we are doing aggregation/combination of multiple values for a given
key it may be useful to iterate over the values associated with that key in the order in which
the mutations were applied (FIFO), instead of the FILO order that seems to occur when using
{{TimeType.LOGICAL}}. 
> I encountered when implemeting a checkAndPut operation that would ensure that the previous
value was expected before putting a new value. In this case, if the previous value was not
as expected, the mutation would be ignored. 
> Perhaps it is useful in a general case?

--
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

Mime
View raw message