> ORMs are typically lowest common denominator for compatibility with many database engines. That really depends on what you mean and the ORM. Typically the la

> ORMs are typically lowest common denominator for compatibility with many database engines. That really depends on what you mean and the ORM. Typically the larger and more popular ORMs can and do take advantage of database specific features, if you let it. Using the database specific feature will prevent you from using the ORM as an abstraction for replacing you DBMS, but outside open source projects that support SQLite, MariaDB and Postgresql, I've never seen that used in professional settings. One system I've worked with had on paper support for DB2, Sybase and MS SQL. It ran solely on MS SQL, the others had not been tested in years and the developers had pulled in so many MS SQL specific features that it was never going to run on neither DB2 nor Sybase ever again.