A team's raw clickstream files in S3 gain new columns every few weeks, and Athena queries break because the catalog table still shows the old layout. Which setup keeps the catalog aligned without manual table edits?
Show answer and explanation
Answer: C
A Glue crawler set to update the table definition when it detects a schema change rewrites the catalog entry to match the files it scans. That keeps downstream Athena queries working as new columns appear. The crawler's schema change policy controls whether it updates, adds, or only logs changes. Job bookmarks only record which input has already been processed. Exporting definitions by hand is a workaround that drifts out of date. Glue Studio is a visual authoring interface and does not watch files for schema changes.
Why the other options are wrong
- A. Job bookmarks track which input has already been processed so reruns skip old data. They do not detect new columns or change the table definition in the catalog.
- B. A weekly export is a manual snapshot that goes stale as soon as the files change. It does not update the catalog automatically, so queries still fail between exports.
- D. Glue Studio is a visual tool for building jobs. Opening a job there does not inspect the source files or change the catalog table's columns.