The monolith has been split into 4 microservices. The global data schema consists of 33 relationships. Each of the 4 microservices owns its own local data schema. 22 of the 33 relationships could be kept within the microservice architecture. This is a percentage value of approximately 67. Both entities of these kept relationships can still be retrieved by a local transaction running in only one microservice. The complexity stays the same as it has been in the monolithic architecture. The local transactions still can profit from the ACID feature that most of the standard relational databases support. 33 percent of the relationships have been destroyed by the data schema split. For those broken relationships, there have to be introduced distributed transactions that span over more than one microservice. Please take a look into the subchapters 3.x.x of this cookbook. For each of the 26 entities, there can be found a description how to create a global transaction that span over more than microservice.
