First, we read and obtain information (schema and data) of the MySQL and SQLServer from the associated XML schema, then store it into PostgreSQL. Finally, we try the database operations on the PostgreSQL side. We assigned the name of each database to the same as that of each RDB name that we used for reasons of simplicity. Figure 6 presents a list of the databases stored in PostgreSQL. In it, it is apparent that the databases named “mysql” and “sqlserver” are added.