Are we able to use Snappy-data to Update a record in Azure Data lake ? OR is Azure data lake append only?

Question

I am currently working on azure data lake with snappy-data integration,I have a query on snappy-data are we able to update the data in the snappy-data to azure data lake storage, or we can append only on the azure data lake storage i searched in forum but i can't reach for that proper solution on it,if any one know about that query on it please share it,thank you.

Answer 1

Azure Data Lake Store, much like HDFS, is an append only store. You can append to a file or replace it altogether. There is no way to update an existing file.

Answer 2

I've achieved MERGE style behaviour in USQL by using a Azure Data Lake table as the middle ground between input and output. Check out my blog post with the code showing how I did it with a series of joins.

https://www.purplefrogsystems.com/paul/2016/12/writing-a-u-sql-merge-statement/

This will give you append behaviour in your output.