How to read and write Map from/to parquet file in Java or Scala?

Question

Looking for a concise example on how to read and write Map from/to parquet file in Java or Scala?

Here is expected structure, usin

Answer 1

Apache Drill is your answer!

Convert to parquet : You can use the CTAS(create table as) feature in drill. By default drill creates a folder with parquet files after executing the below query. You can substitute any query and drill writes the output of you query into parquet files

create table file_parquet as select * from dfs.`/data/file.json`;

Convert from parquet : We also use the CTAS feature here, however we request drill to use a different format for writing the output

alter session set `store.format`='json';
create table file_json as select * from dfs.`/data/file.parquet`;

Refer to http://drill.apache.org/docs/create-table-as-ctas-command/ for more information