What's your usecase for Athena (Really curious how this changes anything)?
You can hook your lambda up to a cloudwatch scheduled event (http://docs.aws.amazon.com/AmazonCloudWatch/latest/events/Sc...). If you don't do much when this happens (like, you exit immediately), then you won't be charged much compute time. Can't find the reference to how often you should ping it to keep it warm, probably varies, IIRC hourly would be plenty.
You can hook your lambda up to a cloudwatch scheduled event (http://docs.aws.amazon.com/AmazonCloudWatch/latest/events/Sc...). If you don't do much when this happens (like, you exit immediately), then you won't be charged much compute time. Can't find the reference to how often you should ping it to keep it warm, probably varies, IIRC hourly would be plenty.