There is a request from our architect team (Services and APIs) who are considering going down the route of micro services and therefore exploring ways to break the single monolithic database. The database stores all the relevant information of companies trading in an exchange some of it being the companies investors, Share prices, currencies that they are trading in.Though not all data is transnational like currency conversion and share prices being EOD they are tightly coupled and have referential integrity with other entities. The idea is to create separate databases. I am evaluating the pros and cons. i do not see a reason why the monolithic database has to split especially when it is so interdependent , the argument is ease of maintenance and deployment which i see as not a strong reason considering the over head to maintain common data across multiple micro services, loosing referential integrity. I am looking for experts opinion here who had to do similar analysis and your findings.