- Yes, in the DLOs (unless using zero copy aka “Data Federation” or “BYOL”, though Data Federation Caching is possible):
DLOs are typed, schema-based, materialized views that reside in storage containers in the data lake (Amazon S3), generally as Apache Parquet files; an open-source, column-oriented file format designed for efficient data storage and retrieval. On top of this, Apache Iceberg provides an abstraction layer between the physical data files and their table representation.
The adoption of these industry standard formats are worth noting, as these file formats are widely supported by other cloud computing providers, and as a result, enable external platforms to integrate to Data Cloud with a zero-copy architecture, for example, Snowflake.
- As for DMOs, then they are just views and are not stored separately:
Data Model Object, or ‘DMO’, enables a virtual, non-materialized view into the data lake. The result from running a query associated with a view is not stored anywhere and is always based on the current data snapshot in the DLOs.
- Source: Cloud Kettle Blog