An Athena JOIN query has become slow and scans more data than before.
Inspect the plan and partition predicates to locate an unintended full scan.
Which diagnostic approach is most appropriate?
Inspect EXPLAIN output, scan statistics, join behavior, and partition pruning to isolate the regression.
Detailed explanation
More permission does not optimize a query plan or reduce data scanned.
More permission does not optimize a query plan or reduce data scanned.
A bucket name does not change a SQL execution plan or scan volume.
A bucket name does not change a SQL execution plan or scan volume.
The plan reveals join and filter behavior, while statistics show whether partition pruning is effective.
The plan reveals join and filter behavior, while statistics show whether partition pruning is effective.
Removing audit records does not improve query execution performance.
Removing audit records does not improve query execution performance.
Check official documentation
Compare the following points with the official documentation.
Amazon Athena EXPLAIN、EXPLAIN ANALYZE、パーティションプルーニングの公式説明を確認する。
What to confirm
性能診断と権限・監査設定の違いを説明できる。
Key points
- EXPLAIN
- Athena
- Scan volume
- Partition pruning
Notes
- Environment: AWS公式DEA-C01試験ガイドと各サービスの公式ドキュメントの確認
- Confirm current AWS service behavior in the official DEA-C01 documentation.
Foundation review
Performance regression
Compare data volume, statistics, partitions, and query changes to find what shifted.
Diagnosis before permission
Authorization and audit settings are separate concerns from query execution strategy.