Question

A data engineer maintains a nightly Athena CREATE TABLE AS SELECT (CTAS) job that transforms raw event logs into a curated Parquet dataset in an S3 prefix, registered as a table in the Glue Data Catalog. The job is orchestrated by Step Functions. Occasionally the workflow retries a failed step, and the engineer notices that the CTAS statement fails on rerun with an error indicating the target location already exists. The team wants the pipeline to be safely re-runnable without manual cleanup. Which approach best resolves this while keeping the transformation logic in Athena?

Accepted Answer

Before running the CTAS, drop the target table and delete the existing S3 output prefix (or write to a new time-partitioned prefix each run), so each execution starts from a clean location.

Answer

Increase the Athena workgroup's query timeout so the CTAS has enough time to overwrite the existing files in place.

Answer

Switch the query to an INSERT INTO statement against the same table so Athena appends results and ignores the existing location.

Answer

Enable Athena query result reuse in the workgroup so repeated runs return cached results instead of rewriting the output.