The main goal is to provide a specific configuration attribute for XML configuration. I.e.

<string-keyed-jdbc-store name="jdbc-store" datasource="java:jboss/datasources/JdbcDS" dialect="MYSQL" ...

instead of having to specify a custom property by

<string-keyed-jdbc-store name="jdbc-store" datasource="java:jboss/datasources/JdbcDS" ... >
     <property name="databaseType">${database.type}</property>
    ...
</string-keyed-jdbc-store>

This will also result in different way of configuring ISPN in embedded mode: .addStore(JdbcBinaryStoreConfigurationBuilder.class).table().databaseType(....) -> .addStore(JdbcBinaryStoreConfigurationBuilder.class)).dialect(...)