accumulo-notifications mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "An (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (ACCUMULO-625) consider augmenting session state with "breadcrumbs"
Date Mon, 14 Jan 2013 16:50:14 GMT

    [ https://issues.apache.org/jira/browse/ACCUMULO-625?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13552870#comment-13552870
] 

An commented on ACCUMULO-625:
-----------------------------

Currently there's a UniqueColumn map/reduce example (org.apache.accumulo.examples.simple.mapreduce.UniqueColumns).
 Ideally I would like to take that example and turn it into an iterator.  Due to the tear
up and tear down factor, is it safe to assume i can only perform this operation per row bases?
So the iterator would find all the distinct column in a single row and the client would have
to perform a final distinct for all the rows?


                
> consider augmenting session state with "breadcrumbs"
> ----------------------------------------------------
>
>                 Key: ACCUMULO-625
>                 URL: https://issues.apache.org/jira/browse/ACCUMULO-625
>             Project: Accumulo
>          Issue Type: Improvement
>          Components: tserver
>            Reporter: Eric Newton
>            Assignee: Keith Turner
>
> Presently, the iterator stack can be created and destroyed at the whim of the tserver
and its buffering needs.  In complex iterations, lower-level iterators can make significant
progress which is not inherently obvious in any returned key.  When the iterator stack is
re-created to continue a query, the last key returned is used to {{seek()}} the iterators.
 Lower-level iterators must re-scan their data to move back to the old position.
> Consider a mechanism to save progress beyond the last key returned.
>   

--
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