Antonio, before i test my app with ca. 60 DBs with your ADORDD i must change some field-names (ex. CHECK or SCHEMA) as they are not allowed in SQL.
I use MSSQL. In my tests indices with UDFs should be avoided (>1000 records). The fastest way is to use only full fieldnames for indexkey. There are some DB-changes recommendable.
For future i will report you all my experiences!