Modern relational databases are all tied together by a well-defined standard for SQL, the latest version published in 2016. But not all SQL implementations follow the standard and even when they do, they often embellish on it and users tend to use the features they see available to them. As a result, migration between databases tends to be a challenging task. In this talk I will give some examples of database migrations I have participated in over the last twenty years and what issues we ran into with each. I will also talk in a more general sense about:
- Database only migration vs application refactoring - which is likely to have the better ROI?
- Analysis tools to help perform migration like Amazon's DMS, SQLines and DBconvert
- Database agnostic replication
- What it means to get support in the Open Source world and how to get it.