URL encoding issue with Databricks Unity Catalog Iceberg REST endpoint - %2F instead of /

[nmellal]

What happens?

When attaching to a Databricks Unity Catalog via the Iceberg REST API, the endpoint gets URL-encoded, causing / to become %2F in the request path. This results in a 404 error.

Expected behavior

The request should be made to:
/api/2.1/unity-catalog/iceberg-rest/v1/catalogs/my_unity_catalog/namespaces

Actual behavior

The request is made to:
/api/2.1/unity-catalog/iceberg-rest/v1/catalogs%2Fmy_unity_catalog/namespaces
Which returns:
HTTP 404 - Not Found

To Reproduce

INSTALL iceberg;
LOAD iceberg;

CREATE SECRET iceberg_secret (
TYPE ICEBERG,
TOKEN 'dapi...'
);

ATTACH 'my_unity_catalog' AS iceberg_catalog (
TYPE ICEBERG,
SECRET iceberg_secret,
ENDPOINT 'https://adb-xxxxxxxx.xx.azuredatabricks.net/api/2.1/unity-catalog/iceberg-rest'
);

select * from iceberg_catalog.my_schema.my_table ;

Error:

request to endpoint 'https://adb-xxxx.azuredatabricks.net/api/2.1/unity-catalog/iceberg-rest/v1/catalogs%2Fmy_unity_catalog/namespaces' returned an error response (HTTP 404). Reason: Not Found

Environment

DuckDB version: 1.4.4
Iceberg extension version: 1095c1f (installed from core)
OS: macOS Version 26.2 (25C56)
Databricks: Azure Databricks with Unity Catalog

[talatuyarer]

Hi @nmellal I solved this issue under this #674 pr. Could you give a try ?

[nmellal]

Hi @talatuyarer

Worked for me.

Had to add duckdb_azure extension
And
Azure SDK dependencies
* azure-identity-cpp
* azure-storage-blobs-cpp
* azure-storage-files-datalake-cpp

[Tmonster]

Hi @nmellal ,

This should be fixed in the coming days, you might also be able to try the unity catalog extension, which is in another repo located here

[Tmonster]

should be fixed with #687