1. A method implemented by data processing apparatus, the method comprising: identifying one or more rows in a relational database that have each been modified since a first point in time, wherein each of the rows is associated with a respective table in the relational database; serializing each of the identified rows into a respective serialized format wherein the serialized format does not include structured query language; for each of the identified rows, updating a respective file in an external representation of the table associated with the row with the respective serialized format of the row wherein the respective file is not stored in the database; creating a first version of the relational database in a version control system using the external representation including one or more of the updated files, wherein the first version of the database comprises one or more files in the version control system; determining one or more differences between one or more files of the first version of the relational database in the version control system and one or more files of a different version of the relational database in the version control system, and executing one or more database commands based on the determined differences so that contents of the relational database are the same as the different version; and detecting a change to the relational database, and creating a second version of the database in the version control system based on the detected change.