[jira] [Commented] (ACCUMULO-906) Combiners documention could be improved

["Billie Rinaldi (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/ACCUMULO-906?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13532463#comment-13532463 ] 

Billie Rinaldi commented on ACCUMULO-906:
-----------------------------------------

Setting "all" to true applies the Combiner to every column instead of just specific columns.  So, if you inserted more data:
{noformat}
> insert mammal cow ellie 1
> insert mammal cow ellie 1
> insert mammal cow ellie 1
> insert mammal cow nell  1
> insert mammal cow nell  1
> insert mammal man eric  1
{noformat}
and then scanned with all=true, you should get
{noformat}
mammal cow:ellie []    3
mammal cow:nell []    2
mammal man:eric []    1
{noformat}
We don't currently support combining values across different columns.
                
> Combiners documention could be improved
> ---------------------------------------
>
>                 Key: ACCUMULO-906
>                 URL: https://issues.apache.org/jira/browse/ACCUMULO-906
>             Project: Accumulo
>          Issue Type: Bug
>    Affects Versions: 1.4.1, 1.4.0, 1.4.2
>            Reporter: Eric Newton
>            Assignee: Eric Newton
>            Priority: Blocker
>             Fix For: 1.5.0, 1.4.3
>
>
> Goal: sum all the values across all columns.
> {noformat}
> > createtable animal
> > deleteiter -n vers -scan -minc -majc
> > setiter -t animal -p 10 -scan -n sum -class org.apache.accumulo.core.iterators.user.SummingCombiner
> SummingCombiner interprets Values as Longs and adds them together.  A variety of encodings (variable length, fixed length, or string) are available
> ----------> set SummingCombiner parameter all, set to true to apply Combiner to every column, otherwise leave blank. if true, columns option will be ignored.: true
> ----------> set SummingCombiner parameter columns, <col fam>[:<col qual>]{,<col fam>[:<col qual>]} escape non-alphanum chars using %<hex>.: 
> ----------> set SummingCombiner parameter lossy, if true, failed decodes are ignored. Otherwise combiner will error on failed decodes (default false): <TRUE|FALSE>: 
> ----------> set SummingCombiner parameter type, <VARLEN|FIXEDLEN|STRING|fullClassName>: STRING
> > insert mammal cow ellie 1
> > insert mammal cow nell  1
> > insert mammal man eric  1
> > scan
> expected: mammal dontcare : dontcare 3
> {noformat}
> Where "dontcare" can come back with anything; I just don't care.
> But I just get this
> {noformat}
> mammal cow:ellie []    1
> mammal cow:nell []    1
> mammal man:eric []    1
> {noformat}
> I can't get the combiner to come back with a sum of mammals or cows.

--
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