Yeah, there doesn't seem to be a UI for actually running the admin tools... however if you navigate to $moodle/admin/tool/dbtransfer/ you can run it from there
I am sorry, you will have to enlighten me here... I would have expected that if I took an SQL dump from a MySQL database and run it in PostGres, that I would be able to use the PostGres database with a minimum of fuss. I understood that SQL was sufficiently developed that it could make this kind of transfer without too many issues. The key here is SQL, and while there may be some angst around triggers, there should be no problems with tables indices and such. Am I correct, or rather, this is not so?
Ahhh so while similaritites are supposed to be a part of SQL, ego and self-interest drive a sufficient number of variations to make any direct changeover difficult. In short, the advertising of each of the companies making a DBMS is considerably less than honest when they claim they are fully compliant with "SQL standards"... but who's "standards"? Their own?
You could argue that SQL is different from ever vendor because SQL was deficient in the first place.
In defence of SQL, it is quite old to begin with, at least in IT terms. The original creators probably didn't imagine how we are using it today. Imagine the problem of DBMS creators wanting to add a feature that is hard to describe (Geospatial data perhaps?) based upon the SQL specification.
So yes, each vendor has come up with their own variations for their own reasons.
At least SQL is sufficiently similar across vendors that applications like Moodle can abstract the database with enough success that when writing Moodle code that interacts with the database you can, within reason, don't need to worry to much about type of database the Moodle installation is using.
