columns:
  - column: "Tier"
  - column: "Description"
rows:
  - "Tier": "**Source cluster(s)**"
    Description: |
      **A dedicated cluster(s)** for [sources](/concepts/sources/).

      {{% best-practices/architecture/upsert-source %}}

  - "Tier": "**Compute/Transform cluster(s)**"
    Description: |
      **A dedicated cluster(s)** for compute/transformation:

      - [Materialized views](/concepts/views/#materialized-views) to persist, in
        durable storage, the results that will be served. Results of
        materialized views are available across all clusters.

        {{< tip >}}
        {{< include-md file="shared-content/stacked-view-consideration.md" >}}
        {{< /tip >}}

      - Indexes, **only as needed**, to make transformation fast (such as
      possibly [indexes on join
      keys](/transform-data/optimization/#optimize-multi-way-joins-with-delta-joins)).

        {{< tip >}}

        From the compute/transformation clusters, do not create indexes on the
        materialized views for the purposes of serving the view results.
        Instead, use the [serving cluster(s)](#tier-serving-clusters) when
        creating indexes to serve the results.

        {{< /tip >}}

  - "Tier": "**Serving cluster(s)**"
    Description: |
      <a name="tier-serving-clusters"></a>
      **A dedicated cluster(s)** for serving queries, including
      [indexes](/concepts/indexes/) on the materialized views. Indexes are local
      to the cluster in which they are created.