We use qumo for ETL purposes by uploading flat files from multiple sources into our SQL database tables (Oracle).
The user interface makes it easy to upload these large sets of records without any issue! I dislike that there isn't an option available as we need this software integrated within Sharepoint Online - so not sure if they can add this? However currently doing fine using what's out now. This product has saved me time during my job role when dealing with importing large amounts of data daily which would be manually uploaded via excel or csv format.