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https://issues.apache.org/jira/browse/BEAM-10124?focusedWorklogId=473607&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-473607
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ASF GitHub Bot logged work on BEAM-10124:
-----------------------------------------
Author: ASF GitHub Bot
Created on: 23/Aug/20 05:51
Start Date: 23/Aug/20 05:51
Worklog Time Spent: 10m
Work Description: abhiy13 commented on a change in pull request #12645:
URL: https://github.com/apache/beam/pull/12645#discussion_r475174519
##########
File path:
sdks/java/io/contextual-text-io/src/main/java/org/apache/beam/sdk/io/contextualtextio/ContextualTextIO.java
##########
@@ -151,8 +157,27 @@
* .apply(ContextualTextIO.readFiles());
* }</pre>
*
- * NOTE: Using {@link
ContextualTextIO.Read#withHasMultilineCSVRecords(Boolean)} introduces a
- * performance penalty: when this option is enabled, the input cannot be split
and read in parallel.
+ * <p>Example 6: reading without recordNum metadata, or only fileName
associated Metadata. (the
+ * Objects would still contain recordNums, but these recordNums would
correspond to their positions
+ * in their respective offsets rather than their positions within the entire
file).
+ *
+ * <pre>{@code
+ * Pipeline p = ...;
+ *
+ * PCollection<RecordWithMetadata> records = p.apply(ContextualTextIO.read()
+ * .from("/local/path/to/files/*.csv")
+ * .setWithoutRecordNumMetadata(true));
+ * }</pre>
+ *
+ * <p>NOTE: When using {@link
ContextualTextIO.Read#withHasMultilineCSVRecords(Boolean)} this
+ * option, a single reader will be used to process the file, rather than
multiple readers which can
+ * read from different offsets. For a large file this can result in lower
performance.
+ *
+ * <p>NOTE: Use {@link Read#withoutRecordNumMetadata()} when recordNum
metadata is not required or
+ * when only metadata associated with filenames is required, Not using this
option introduces a
+ * shuffle step which increases the resources used by the pipeline. <b>This
option is set to false
+ * by default. Meaning that the shuffle step will be performed, set it to
false to avoid the shuffle
Review comment:
Done.
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Issue Time Tracking
-------------------
Worklog Id: (was: 473607)
Remaining Estimate: 1,334h 40m (was: 1,334h 50m)
Time Spent: 9h 20m (was: 9h 10m)
> ContextualTextIO - An IO that is provides metadata about the line.
> -------------------------------------------------------------------
>
> Key: BEAM-10124
> URL: https://issues.apache.org/jira/browse/BEAM-10124
> Project: Beam
> Issue Type: New Feature
> Components: io-ideas
> Reporter: Reza ardeshir rokni
> Priority: P2
> Original Estimate: 1,344h
> Time Spent: 9h 20m
> Remaining Estimate: 1,334h 40m
>
> There are two important Source IO's that allow for dealing with text files
> FileIO and TextIO. When the requirements go beyond the scope of TextIO we ask
> the end user to make use of FileIO and go it on their own.
> We want to correct this experience by creating a more feature rich TextIO
> which can return along with each line of data contextual information about
> the line. For example the file that it came from, and the ordinal position of
> the line within the file.
> Another area that we would like to deal with is more formal support for CSV
> files by allowing compliance to RFC4180 files. Specifically the RFC allows
> for line breaks (CRLF) to be used within fields within double quotes.
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