Merge pull request #4 from cmu-db/yenjuw

add design rationale and tradeoff to proposal

doc/design_doc.md

@@ -11,11 +11,23 @@
 >Explain the input and output of the component, describe interactions and breakdown the smaller components if any. Include diagrams if appropriate.
 
 ## Design Rationale
->Explain the goals of this design and how the design achieves these goals. Present alternatives considered and document why they are not chosen.
+* Correctness:
+  * The catalog service ensures data consistency and correctness by adhering to the Iceberg Catalog REST interface.
+  * Data durability mechanisms will be implemented to prevent data loss during restarts.
+* Performance:
+  * Optimized data retrieval and storage strategies to minimize latency in metadata access.
+  * Efficient indexing mechanisms to speed up metadata search operations.
+  * Caching strategies to reduce redundant metadata queries and enhance overall performance.
+* Engineering Complexity / Maintainability:
+  * The microservices architecture simplifies maintenance by encapsulating each building block.
+  * Code modularity and clear interfaces facilitate easier updates and improvements.
+* Testing:
+  * Comprehensive testing plans cover correctness through unit tests and performance through long-running regression tests. Unit tests focus on individual components of the catalog service, while regression tests evaluate system-wide performance and stability.
+* Other Implementations:
+  * Considered alternative implementations, including a monolithic catalog structure and alternative REST specifications.
+  * Chose the Iceberg Catalog REST interface due to its industry adoption, standardization, and compatibility with various systems.
 
 ## Testing Plan
->How should the component be tested?
-
 To ensure the quality and the performance of the catalog implemented, a comprehensive testing strategy is a must. Our testing strategy will include both functional and non-functional aspects of our catalog service. 
 
 * Functional testing
@@ -26,10 +38,9 @@ To ensure the quality and the performance of the catalog implemented, a comprehe
   * Performance evaluation: We will set up a performance baseline to compare the performance of our implementation. We can measure different metrics, for example, response time, throughput, etc.
   * Scalability test: We will try to test our implementation under increased load and ensure the correctness and efficiency at the same time.
 
-
-
 ## Trade-offs and Potential Problems
->Write down any conscious trade-off you made that can be problematic in the future, or any problems discovered during the design process that remain unaddressed (technical debts).
+* Balancing between metadata retrieval speed and storage efficiency.
+* Striking a balance between query performance and resource utilization.
 
 ## Glossary (Optional)
 >If you are introducing new concepts or giving unintuitive names to components, write them down here.