Supported Catalogs¶

Beyond the natively maintained Directory Catalog and REST Catalog specifications, Lance supports integration with external catalog systems through the Namespace Client Spec.

What are Supported Catalogs?¶

Supported catalogs are implementation specs for external catalog systems. They describe how a specific catalog system (such as Apache Polaris, Unity Catalog, or Apache Hive Metastore) integrates with Lance. Each implementation defines:

How catalog objects map to Lance Namespace concepts
How to identify Lance tables within the catalog
How each Namespace Client operation is fulfilled by the catalog

Available Catalogs¶

Implementation specs are maintained in the lance-namespace-impls repository. Supported catalogs include:

Apache Polaris: Integration with Polaris Catalog for multi-engine governance
Unity Catalog: Integration with Databricks Unity Catalog
Apache Hive Metastore: Integration with Hive Metastore for legacy warehouse compatibility
Apache Iceberg REST Catalog: Integration with Iceberg's REST Catalog protocol
AWS Glue Data Catalog: Integration with AWS Glue for cloud-native deployments

Contributing¶

Catalog implementations can be owned by external parties without needing to go through the Lance community voting process to be adopted. Anyone can provide additional implementation specs outside the core Lance Namespace spec.

To contribute a new catalog implementation, follow the Implementation Spec Template which defines the standard structure for describing how a catalog system integrates with the Namespace Client.