Manifest List

Manifest List is a metadata file in the Apache Iceberg format that represents a single snapshot of a table. It lists all the manifest files that make up that snapshot, providing a unified view of the table’s state.

How it Works

When a write transaction commits, Iceberg generates a new snapshot mapped to a manifest list.

• Snapshot Metadata: Contains the snapshot ID, parent snapshot ID, creation timestamp, and the summary of changes (e.g., records added).
• Manifest Tracking: Lists the file paths of all active manifest files associated with the snapshot.
• Partition Summary: Stores the range of partition values contained in each manifest file. Query engines scan these summaries to skip entire manifest files during query execution.

Lakehouse & Agentic Relevance

In a data lakehouse, manifest lists enable transaction isolation and time travel capabilities. Because each manifest list represents a complete snapshot, query engines can access previous table states. If an autonomous agent needs to query historical data or run transaction-consistent audits, it leverages these snapshot states. Dremio queries the manifest list to identify the active files for any given snapshot, executing queries without locking the table.