Abstract: With the development of open source database technology, more business systems are migrating from commercial databases to open source databases. System migration, which keeps the data model unchanged, has a more powerful means to prove the correctness of its migration. By comparing the differences between the two logs in real-time or quasi-real-time, we can conclude whether the system works in accordance with expectations, and provide more basis for the application of checking problems.

Key words: database, migrating, comparison