Files
impala/java/TableFlattener
Joe McDonnell 26398855bf IMPALA-10930: Bump the Java artifact versions to 4.1.0-SNAPSHOT
This changes the Maven pom.xml files to use verison
4.1.0-SNAPSHOT rather than 4.0.0-SNAPSHOT. In the
past, these versions were a fixed value, but that
changed with IMPALA-10198. This is a new step that
needs to happen on each release.

Testing:
 - Ran a build

Change-Id: I10a589b4fbc15048199943a0e06d079f57840239
Reviewed-on: http://gerrit.cloudera.org:8080/18390
Reviewed-by: Tamas Mate <tmater@apache.org>
Tested-by: Impala Public Jenkins <impala-public-jenkins@cloudera.com>
2022-04-11 16:06:46 +00:00
..

This is a tool to convert a nested dataset to an unnested dataset. The source and/or
destination can be the local file system or HDFS.

Structs get converted to a column (with a long name). Arrays and Maps get converted to
a table which can be joined with the parent table on id column.

$ mvn exec:java \
    -Dexec.mainClass=org.apache.impala.infra.tableflattener.Main \
    -Dexec.arguments="file:///tmp/in.parquet,file:///tmp/out,-sfile:///tmp/in.avsc"

$ mvn exec:java \
    -Dexec.mainClass=org.apache.impala.infra.tableflattener.Main \
    -Dexec.arguments="hdfs://localhost:20500/nested.avro,file://$PWD/unnested"

There are various options to specify the type of input file but the output is always
parquet/snappy.

For additional help, use the following command:
$ mvn exec:java \
    -Dexec.mainClass=org.apache.impala.infra.tableflattener.Main -Dexec.arguments="--help"

This is used by testdata/bin/generate-load-nested.sh.