I'm new on Apache Beam and I'm developing a pipeline to get rows from JDBCIO and send them to BigQueryIO. I'm converting the rows to avro files with `withAvroFormatFunction` but it is creating a new file for each row returned by JDBCIO. The same for `withFormatFunction` with json files. 

It is so slow to run locally with DirectRunner because it uploads a lot of files to Google Storage. Is this approach good for scaling on Google Dataflow? Is there a better way to deal with it?

Thanks