Appendix: Alternative cluster architectures
If the recommended three-tier architecture is infeasible or unnecessary due to low volume or a non-production setup, a two-tier or a one-tier architecture may suffice.
Two-tier architecture
If the recommended three-tier architecture is infeasible or unnecessary due to low volume or a non-production setup, a two-tier architecture may suffice. A two-tier architecture consists of:
| Tier | Description | 
|---|---|
| Source cluster(s) | A dedicated cluster(s) for sources. In addition, for upsert sources: 
 | 
| Compute/Transform + Serving cluster | A dedicated cluster for both compute/transformation and serving queries: 
 With a two-tier architecture, compute and queries compete for the same cluster resources. 
  
    💡 Tip:  Except for when used with a sink,
subscribe, or temporal
filters, avoid creating
materialized views on a shared cluster used for both compute/transformat
operations and serving queries. Use indexed views instead.
 | 
Benefits of a two-tier architecture include:
- 
Support for blue/green deployments 
- 
More cost effective than a three-tier architecture. 
However, with a two-tier architecture:
- 
Compute/transform operations and queries compete for the same cluster resources. 
- 
Cluster restarts require rehydration of the indexes on views. 
One-tier architecture
If the recommended three-tier architecture is infeasible or unnecessary due to low volume or a non-production setup, a one-tier architecture may suffice for your sources, compute objects, and query serving needs.
| Tier | Description | 
|---|---|
| All-in-one cluster | A cluster for sources, compute/transformation and serving queries: 
 With a 1-tier single-cluster architecture, sources, compute, and queries compete for the same cluster resources. 
  
    💡 Tip:  Except for when used with a sink,
subscribe, or temporal
filters, avoid creating
materialized views on a shared cluster used for both compute/transformat
operations and serving queries. Use indexed views instead.
 | 
Benefits of a one-tier architecture include:
- Cost effective
Limitations of a one-tier architecture include:
- 
Sources, compute objects, and queries compete for cluster resources. 
- 
Blue/green deployment is unsupported since sources would need to be dropped and recreated, putting strain on your upstream system during source recreation. To support blue/green deployments, use a two-tier architecture by moving compute objects to a new cluster (i.e., recreating compute objects in a new cluster). 
- 
Cluster restarts require rehydration of the indexes on views.