That said, ADO.NET database drivers should be faster or have the same data access speed as the ones used in Delphi, at least for major data providers like MS SQL, PostgreSQL, Oracle etc.
Yes, you would be able to use DA LINQ, however it will be limited.
It is possible to switch DA LINQ data provider into an alternate data access mode.
In this mode DA LINQ uses DynamicWhere statements to represent queries. This means that such data queries can be processed by Delphi server too. However this comes at a price - not every valid DA LINQ query can be processed in that mode. F.e. function calls in the WHERE clause, table joins etc cannot be represented as a DynamicWhere statement, so they cannot be processed in that alternate mode.
This means that this query would be successfully processed:
var query := from j in self.LinqAdapter.GetTable<Jobs>()
where (j.OrderDateField.Day = 1) and (j.OrderDateField.Month = 8)
And this one contains method calls (
var res := from x
where x.CustomerIDField.ToUpper().Contains('F') select x;
so it cannot be represented using
DynamicWhere only. In case of DA SQL this query would be translated into a SQL statement containing corresponding database server function calls.