hadoop-common-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Chris Douglas (JIRA)" <j...@apache.org>
Subject [jira] Commented: (HADOOP-449) Generalize the SequenceFileInputFilter to apply to any InputFormat
Date Wed, 06 Feb 2008 21:47:08 GMT

    [ https://issues.apache.org/jira/browse/HADOOP-449?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12566362#action_12566362
] 

Chris Douglas commented on HADOOP-449:
--------------------------------------

* It looks like one can't meaningfully nest FilterInputFormats. A check in initBaseInputFormat
that rejects an attempt to do this would probably be a good idea.
* IIRC, Configuration::IntegerRanges is limited to positive integers, so the default range
of (Integer.MIN_VALUE + "-" + Integer.MAX_VALUE) in IntRangeFilter::setConf may be invalid.
* RangeFilter should probably accept a WritableComparator to support user types and an alternative
syntax for projections
* Would it be too constraining to limit SetFilter and ItemFilter to Text? Filtering based
on the string representation of Writables seems like an overly general strategy.
The patch looks good; this should be very useful.

> Generalize the SequenceFileInputFilter to apply to any InputFormat
> ------------------------------------------------------------------
>
>                 Key: HADOOP-449
>                 URL: https://issues.apache.org/jira/browse/HADOOP-449
>             Project: Hadoop Core
>          Issue Type: Improvement
>          Components: mapred
>    Affects Versions: 0.17.0
>            Reporter: Owen O'Malley
>            Assignee: Enis Soztutar
>             Fix For: 0.17.0
>
>         Attachments: filterinputformat_v1.patch
>
>
> I'd like to generalize the SequenceFileInputFormat that was introduced in HADOOP-412
so that it can be applied to any InputFormat. To do this, I propose:
> interface WritableFilter {
>    boolean accept(Writable item);
> }
> class FilterInputFormat implements InputFormat {
>   ...
> }
> FilterInputFormat would look in the JobConf for:
>    mapred.input.filter.source = the underlying input format
>    mapred.input.filter.filters = a list of class names that implement WritableFilter
> The FilterInputFormat will work like the current SequenceFilter, but use an internal
RecordReader rather than the SequenceFile. This will require adding a next(key) and getCurrentValue(value)
to the RecordReader interface, but that will be addressed in a different issue.

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.


Mime
View raw message