Answer: Directory listing, File notification

According to the official Databricks documentation: https://docs.databricks.com/aws/en/ingestion/cloud-object-storage/auto-loader/ , Auto Loader supports two file detection modes: Directory listing mode – Periodically lists files in the source directory and compares them to previously processed files. File notification mode – Uses cloud-native notification services (e.g., AWS SQS, Azure Event Grid, GCP Pub/Sub) to detect new files more efficiently. Checkpointing is used to track processed files and ensure exactly-once processing, but it is not a file detection method. Watermarking is used in streaming to handle late-arriving data, not for detecting new files.

Author: LeetQuiz Editorial Team