Is it possible to delete data stored in S3 through an Athena query? I have some rows I have to delete from a couple of tables (they point to separate buckets in S3).
Use AWS Glue for that.
Load your data, delete what you need to delete, save the data back.
Now you can also delete files from s3 and merge data: https://aws.amazon.com/about-aws/whats-new/2020/01/aws-glue-adds-new-transforms-apache-spark-applications-datasets-amazon-s3/