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From Christian Tzolov <christian.tzo...@gmail.com>
Subject Re: RFC 4180 compliant CSV format
Date Tue, 19 Mar 2013 13:54:10 GMT
@Josh, most of the time I can manage to steer away from multiline records
but with gov. organisations it is difficult to alter what they
have considered as a 'standard'.

Can you please elaborate on your idea for named records/rows?

@Harsh, thanks for the references. I remember I had some issues with
OpenCSV (either the iterator suport or some RFC4180 limitations). But I
would check the other sources.

Thanks,
Chris



On Tue, Mar 19, 2013 at 12:44 AM, Harsh J <harsh@cloudera.com> wrote:

> Does OpenCSV (http://opencsv.sourceforge.net/#what-features) support
> your format? There's a Hive wrapper for it:
> http://ogrodnek.github.com/csv-serde and IIRC also a newer InputFormat
> at https://github.com/mvallebr/CSVInputFormat (via
> https://issues.apache.org/jira/browse/MAPREDUCE-2208).
>
> On Mon, Mar 18, 2013 at 3:44 PM, Christian Tzolov
> <christian.tzolov@gmail.com> wrote:
> > Hi,
> >
> > I am working on ETL projects that consume and produce data in the RFC4180
> > [1] CSV format. Although unreliable IMO, this RFC is used as an exchange
> > format by several Dutch government agencies.
> >
> > The RFC4180 spec supports multi-line fields (e.g. fields with line
> > breaks) and escaping of double quotes and delimiters within fields.
> Because
> > of the multi-line feature one can't use directly the
> > FileInputFormat/TextInputFormat or LineRecordReader implementations.
> > Furthermore as I see it the input splitting must be disabled (not sure if
> > any efficient splitting strategy is possible at all).
> >
> > There are several java libraries that provide some RFC4180 support [3].
> For
> > Pig a slightly modified CSVExcelStorage UDF [2] seems to do the job (not
> > sure about the input splitting though). Also the "Hadoop in Practice"
> > example [4] does not support the multi-line fields.
> >
> > Has someone used similar 'multi-line fields' formats? I wonder how common
> > is this use case.
> >
> > Also shall we provide support for it in Crunch?
> >
> > Cheers,
> > Chris
> >
> > [1]  RFC 4180 - http://tools.ietf.org/html/rfc4180
> > [2]  PIG CVSExcelStorage UDF -
> >
> http://svn.apache.org/repos/asf/pig/trunk/contrib/piggybank/java/src/main/java/org/apache/pig/piggybank/storage/CSVExcelStorage.java
> > [3]  jCSV, OpenCSV, SuperCSV
> > [4]
> >
> https://github.com/alexholmes/hadoop-book/blob/master/src/main/java/com/manning/hip/ch3/csv/CSVInputFormat.java
>
>
>
> --
> Harsh J
>

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