Technology for database migration using java?

Question

Java

Hello! Need help making a decision, thanks in advance! The task is to develop a tool (service) for migrating various databases in real (or close to real) time to Java. For example, there is a site that uses PostgreSQL, it needs to be transferred to a new server and it will already use MySQL. At the moment I have several options: SymmetricDS, JavaLite, Liquibase, Flyway or use Hibernate or Jdbc. You need to develop from scratch and I have no experience. Do you have ready-made developments or advice on how to properly build the application architecture and what technology is better to choose. I liked SymmetricDS or Hibernate the most (but this is just another bike). There is a similar solution. But you need your own. Also, how many people should be in the team and for what period of time is it really possible to do this?

Answer 1

Liquibase, Flyway are used for, so to speak, the evolution of the data schema during the life of the application without data loss.
These tools do not allow you to change the database dialect. I don't know about the rest.
// Specifically structured the sentence to avoid the word "migration". Sir, what meaning do you put into it? Let's move from sqlite to oracle?

Answer 2

If I understand correctly, you need a tool that at a particular moment will transfer the database with data to another server / engine. Roughly speaking, now everything works for you on MySQL, tomorrow they gave you the go-ahead - we are going to PostgreSQL and Orasle. And you - tyk and moved.
And so, I normally working such tool did not see. There are a lot, without a doubt, but firstly, the majority wants money, and secondly, they often lag on big data and ask for user intervention.
I myself wrote a tool for "passing" schemas and data from MSSQL <=> PostgreSQL <=> MSSQL. At the same time, this tool only overtook the data. And there were problems, the same PostgreSQL does not disable checking of foreign keys, and, accordingly, you need to distill the schema very carefully and not in alphabetical order.
An example of another problem - yes, big data, everything lay down for me and measured for a long time (although I drove in batches according to a custom number of records, etc.).
I transferred database schemas with other tools, here you have Liquebase or self-written schema deployment from Hibernate.