how does Athena work for unstructured files
It depends on what you would want Athena to do. Athena does work on unstructured files, but the information it returns would be very different and limited. If you’re looking to transform your unstructured data into something structured, you have some options of using other services to balance those out.
If you’re looking to search masses of unstructured data for particular strings, like looking for words in text files, you might be better off using something like ElasticSearch rather than Athena