Update docs index page.

docs/source/index.rst

@@ -60,7 +60,55 @@ Mosaic provides:
    * optimisations for performing point-in-polygon joins using an approach we co-developed with Ordnance Survey (`blog post <https://databricks.com/blog/2021/10/11/efficient-point-in-polygon-joins-via-pyspark-and-bng-geospatial-indexing.html>`_); and
    * the choice of a Scala, SQL and Python API.
 
-For Mosaic versions < 0.4.0 please use the `0.3.x docs <https://databrickslabs.github.io/mosaic/0.3.x/index.html>`_.
+.. note::
+   For Mosaic versions < 0.4.0 please use the `0.3.x docs <https://databrickslabs.github.io/mosaic/v0.3.x/index.html>`_.
+
+
+Version 0.4.0
+=============
+
+We recommend using Databricks Runtime versions 13.3 LTS with Photon enabled.
+
+.. warning::
+   Mosaic 0.4.x series only supports DBR 13.x DBRs.
+   If running on a different DBR it will throw an exception:
+
+   **DEPRECATION ERROR: Mosaic v0.4.x series only supports Databricks Runtime 13. You can specify `%pip install 'databricks-mosaic<0.4,>=0.3'` for DBR < 13.**
+
+As of the 0.4.0 release, Mosaic issues the following ERROR when initialized on a cluster that is neither Photon Runtime nor Databricks Runtime ML `ADB <https://learn.microsoft.com/en-us/azure/databricks/runtime/>`_ | `AWS <https://docs.databricks.com/runtime/index.html/>`_ | `GCP <https://docs.gcp.databricks.com/runtime/index.html/>`_ :
+
+**DEPRECATION ERROR: Please use a Databricks Photon-enabled Runtime for performance benefits or Runtime ML for spatial AI benefits; Mosaic 0.4.x series restricts executing this cluster.**
+
+As of Mosaic 0.4.0 (subject to change in follow-on releases)
+   * No Mosaic SQL expressions cannot yet be registered with `Unity Catalog <https://www.databricks.com/product/unity-catalog>`_ due to API changes affecting DBRs >= 13.
+   * `Assigned Clusters <https://docs.databricks.com/en/compute/configure.html#access-modes>`_ : Mosaic Python, R, and Scala APIs.
+   * `Shared Access Clusters <https://docs.databricks.com/en/compute/configure.html#access-modes>`_ : Mosaic Scala API (JVM) with Admin `allowlisting <https://docs.databricks.com/en/data-governance/unity-catalog/manage-privileges/allowlist.html>`_ ; Python bindings to Mosaic Scala APIs are blocked by Py4J Security on Shared Access Clusters.
+
+.. note::
+   As of Mosaic 0.4.0 (subject to change in follow-on releases)
+
+   * `Unity Catalog <https://www.databricks.com/product/unity-catalog>`_ : Enforces process isolation which is difficult to accomplish with custom JVM libraries; as such only built-in (aka platform provided) JVM APIs can be invoked from other supported languages in Shared Access Clusters.
+   * `Volumes <https://docs.databricks.com/en/connect/unity-catalog/volumes.html>`_ : Along the same principle of isolation, clusters (both assigned and shared access) can read Volumes via relevant built-in readers and writers or via custom python calls which do not involve any custom JVM code.
+
+
+
+Version 0.3.x Series
+====================
+
+We recommend using Databricks Runtime versions 12.2 LTS with Photon enabled.
+For Mosaic versions < 0.4.0 please use the `0.3.x docs <https://databrickslabs.github.io/mosaic/v0.3.x/index.html>`_.
+
+.. warning::
+   Mosaic 0.3.x series does not support DBR 13.x DBRs.
+
+As of the 0.3.11 release, Mosaic issues the following WARNING when initialized on a cluster that is neither Photon Runtime nor Databricks Runtime ML `ADB <https://learn.microsoft.com/en-us/azure/databricks/runtime/>`_ | `AWS <https://docs.databricks.com/runtime/index.html/>`_ | `GCP <https://docs.gcp.databricks.com/runtime/index.html/>`_ :
+
+**DEPRECATION WARNING: Please use a Databricks Photon-enabled Runtime for performance benefits or Runtime ML for spatial AI benefits; Mosaic will stop working on this cluster after v0.3.x.**
+If you are receiving this warning in v0.3.11+, you will want to begin to plan for a supported runtime. The reason we are making this change is that we are streamlining Mosaic internals to be more aligned with future product APIs which are powered by Photon. Along this direction of change, Mosaic has standardized to JTS as its default and supported Vector Geometry Provider.
+
+
+
+
 
 Documentation
 =============