Merge pull request #13 from tonybka/enhancement/tonybka/edit-readme-2…

…0230415

Update README.md

README.md

@@ -5,6 +5,11 @@ Fundamental elements of DDD implementation in Golang microservice
 
 
 # Components
+## Application Layer
+- DTOs, Mapper & Presenter
+- Request handlers
+- Event handlers
+- Message Publisher
 ## Domain Layer
 ### Entity
 - Mutable, has identity
@@ -16,18 +21,3 @@ Fundamental elements of DDD implementation in Golang microservice
 ## Persistence Layer
 - Data Model
 - Repository
-
-
-# Q&A
-## Why UUIDv1 for entity's identity?
-### Reasons (short)
-- Need to have random, unique identity values for entities
-- To decouple domain layer from persistence layer, we should not use table row's id for entity's identity
-- MySQL support storing UUIDv1 as BINARY(16) in database which saves storage space
-- Comparing UUIDv1 values is faster than comparing values of the other versions (they have common dash-separated groups if they are generated on a same machine)
-
-### References
-- [Making UUIDs More Performant in MySQL](https://emmer.dev/blog/making-uuids-more-performant-in-mysql/)
-- [Storing UUID Values in MySQL Tables](https://dev.mysql.com/blog-archive/storing-uuid-values-in-mysql-tables/)
-- [GUID/UUID Performance Breakthrough](http://mysql.rjweb.org/doc.php/uuid)
-- [Storing UUID Values in MySQL](https://www.percona.com/blog/2014/12/19/store-uuid-optimized-way/)