Various methods the
core/DbHelper helper classes execute MySQL specific statements. In order to support alternative databases these statements should be moved to new methods defined in
core/Db/AdapterInterface and implemented by the chosen PDO Adapter.
core/DbHelper, identify those which are very specific to MySQL.
core/DbHelpermethod to call the new methods on the PDO adapter.
An example of a MySQL specific helper function is
DbHelper::getDefaultCharset()) which fails on TiDB, SingleStore and likely other databases.