mirror of
https://github.com/apache/impala.git
synced 2025-12-19 18:12:08 -05:00
1cf5bc6e79
Change-Id: I21c3b823c1b0db198d442d155c01d4cfd3a5c522 Reviewed-on: http://gerrit.cloudera.org:8080/20534 Reviewed-by: Impala Public Jenkins <impala-public-jenkins@cloudera.com> Tested-by: Impala Public Jenkins <impala-public-jenkins@cloudera.com>
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.