An analytics application needs to pull only a handful of columns from large CSV objects stored in S3, rather than downloading and parsing entire multi-gigabyte files in the application. Which S3 feature lets the application run a SQL-like expression against an object and receive back only the matching data?
- S3 Transfer Acceleration
- S3 Cross-Region Replication
- S3 Select
- S3 Glacier Bulk Retrieval
Why C? And why not the others?
Correct answer: C. S3 Select
S3 Select lets an application run a SQL-like expression directly against an object stored in S3 and retrieve only the matching rows or columns, instead of pulling down and parsing the entire object client-side, which cuts both the data transferred and the latency for large CSV, JSON, or Parquet files. Transfer Acceleration only speeds up the network path for uploading or downloading whole objects over long distances; it does not let you filter the contents of an object. Cross-Region Replication copies whole objects to a bucket in another Region for redundancy or latency reasons and has no query capability at all. Glacier Bulk Retrieval is a slow, low-cost restore option for archived objects in Glacier storage classes; it retrieves entire archived objects and is unrelated to running a query against object contents.
Source: AWS S3 docs: Selecting content from objects with S3 Select