Athena execution limits.

Amazon Athena has certain execution limits in place to ensure the service operates efficiently and fairly for all users. As of my last knowledge update in September 2021, here are some of the key limits:

1. Maximum Query Duration:
   • Athena queries have a maximum allowed execution time. For interactive queries, this is typically set to 30 minutes.
2. Maximum Query Size:
   • The maximum size of a query result set is 10 GB in CSV or JSON format.
3. Maximum Concurrent Queries:
   • Each AWS account has a limit on the number of concurrent queries they can run at the same time. This limit is determined by your AWS service quota.
4. Result Set Pagination Limit:
   • When retrieving results, you can paginate through a maximum of 1,000 rows per request.
5. Maximum Named Query per Account:
   • You can define a maximum of 1,000 named queries per AWS account.
6. Maximum Partitions per Table:
   • A table in Athena can have up to 20,000 partitions.
7. Maximum Number of Tables per Database:
   • A database in Athena can have up to 20,000 tables.
8. Maximum Number of Databases per Account:
   • You can create up to 1,000 databases per AWS account.
9. Maximum Open Prepared Statements:
   • You can have up to 50 open prepared statements per connection.
10. Concurrent Query Execution Per Database:
    • Each database in Athena can run multiple queries concurrently. The limit is not publicly disclosed.
11. Maximum Allowed Table Name Length:
    • Table names can be up to 128 characters in length.

Please note that these limits are based on the state of the service as of September 2021. AWS may adjust these limits over time, so I recommend consulting the official AWS Athena documentation or checking the AWS Service Quotas page for the most up-to-date information.

If you need to request a limit increase or if you have specific use cases that may require higher limits, you can contact AWS Support to discuss your requirements.