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https://issues.apache.org/jira/browse/BEAM-10030?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Saurabh Joshi updated BEAM-10030:
---------------------------------
Description:
Apache Beam has TextIO which can read text based files line by line, delimited
by either a carriage return, newline, or a carriage return and a newline. This
approach does not support CSV files which have records that span multiple
lines. This is because there could be fields where there is a newline inside
the double quotes.
This Stackoverflow question is relevant for a feature that should be added to
Apache Beam:
[https://stackoverflow.com/questions/51439189/how-to-read-large-csv-with-beam]
I can think of two libraries we could use for handling CSV files. The first one
is using Apache Commons CSV library. Here is some example code which can use
CSVRecord class for reading and writing CSV records:
{{{color:#172b4d}{{PipelineOptions options = PipelineOptionsFactory.create();}}
{{Pipeline pipeline = Pipeline.create(options);}}
{{PCollection<CSVRecord> records = pipeline.apply("ReadCSV",
CSVIO.read().from("input.csv"));}}
records.apply("WriteCSV", CSVIO.write().to("output.csv"));{color}}}
Another library we could use is Jackson CSV, which allows users to specify
schemas for the columns:
[https://github.com/FasterXML/jackson-dataformats-text/tree/master/csv]
The crux of the problem is this: can we read and write large CSV files in
parallel? If so, would it be good to have a feature where Apache Beam supports
reading/writing CSV files?
was:
Apache Beam has TextIO which can read text based files line by line, delimited
by either a carriage return, newline, or a carriage return and a newline. This
approach does not support CSV files which have records that span multiple
lines. This is because there could be fields where there is a newline inside
the double quotes.
This Stackoverflow question is relevant for a feature that should be added to
Apache Beam:
[https://stackoverflow.com/questions/51439189/how-to-read-large-csv-with-beam]
I can think of two libraries we could use for handling CSV files. The first one
is using Apache Commons CSV library. Here is some example code which can use
CSVRecord class for reading and writing CSV records:
{color:#172b4d}{{PipelineOptions options = PipelineOptionsFactory.create();}}
{{Pipeline pipeline = Pipeline.create(options);}}
{{PCollection<CSVRecord> records = pipeline.apply("ReadCSV",
CSVIO.read().from("input.csv"));}}
{{ records.apply("WriteCSV", CSVIO.write().to("output.csv"));}}{color}
Another library we could use is Jackson CSV, which allows users to specify
schemas for the columns:
[https://github.com/FasterXML/jackson-dataformats-text/tree/master/csv]
The crux of the problem is this: can we read and write large CSV files in
parallel? If so, would it be good to have a feature where Apache Beam supports
reading/writing CSV files?
> Add CSVIO for Java SDK
> ----------------------
>
> Key: BEAM-10030
> URL: https://issues.apache.org/jira/browse/BEAM-10030
> Project: Beam
> Issue Type: New Feature
> Components: io-ideas
> Reporter: Saurabh Joshi
> Priority: P2
>
> Apache Beam has TextIO which can read text based files line by line,
> delimited by either a carriage return, newline, or a carriage return and a
> newline. This approach does not support CSV files which have records that
> span multiple lines. This is because there could be fields where there is a
> newline inside the double quotes.
> This Stackoverflow question is relevant for a feature that should be added to
> Apache Beam:
> [https://stackoverflow.com/questions/51439189/how-to-read-large-csv-with-beam]
> I can think of two libraries we could use for handling CSV files. The first
> one is using Apache Commons CSV library. Here is some example code which can
> use CSVRecord class for reading and writing CSV records:
> {{{color:#172b4d}{{PipelineOptions options =
> PipelineOptionsFactory.create();}}
> {{Pipeline pipeline = Pipeline.create(options);}}
> {{PCollection<CSVRecord> records = pipeline.apply("ReadCSV",
> CSVIO.read().from("input.csv"));}}
> records.apply("WriteCSV", CSVIO.write().to("output.csv"));{color}}}
> Another library we could use is Jackson CSV, which allows users to specify
> schemas for the columns:
> [https://github.com/FasterXML/jackson-dataformats-text/tree/master/csv]
> The crux of the problem is this: can we read and write large CSV files in
> parallel? If so, would it be good to have a feature where Apache Beam
> supports reading/writing CSV files?
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