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https://issues.apache.org/jira/browse/HADOOP-4065?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12629298#action_12629298
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Mahadev konar commented on HADOOP-4065:
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we at yahoo have been working on similar kind of files where data is just
stored as binary data and is splittable.
http://issues.apache.org/jira/browse/HADOOP-3315
the spec is old and needs to be updated. TFile is meant to be a sequence file
replacement.
A TFile is a container of key-value pairs. Both keys and values are type-less
byte arrays. Keys can be up to 64KB, value length is not restricted. TFile
further provides the following features:
- Block Compression.
- Named meta data blocks.
- Sorted or unsorted keys.
- Seek by key or by file offset.
We will update the specs on HADOOP-3315 by the end of this week.
> support for reading binary data from flat files
> -----------------------------------------------
>
> Key: HADOOP-4065
> URL: https://issues.apache.org/jira/browse/HADOOP-4065
> Project: Hadoop Core
> Issue Type: Bug
> Components: mapred
> Reporter: Joydeep Sen Sarma
>
> like textinputformat - looking for a concrete implementation to read binary
> records from a flat file (that may be compressed).
> it's assumed that hadoop can't split such a file. so the inputformat can set
> splittable to false.
> tricky aspects are:
> - how to know what class the file contains (has to be in a configuration
> somewhere).
> - how to determine EOF (would be nice if hadoop can determine EOF and not
> have the deserializer throw an exception (which is hard to distinguish from
> a exception due to corruptions?)). this is easy for non-compressed streams -
> for compressed streams - DecompressorStream has a useful looking
> getAvailable() call - except the class is marked package private.
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