Scenario:
We are going to be moving from retail system using a MySql Database to a new system that uses SQL Server. I am working on rewriting a very simple program that puts the results of a simple SQL select statement into a QSqlQueryModel, which is then used as a source model for a QSortFilterProxyModel (to allow the user to sort on columns) and displayed in a QTableView. With MySql the data is returned and displayed basically instantaneously, while the same amount of data (100 rows by ~20 columns) using ODBC takes about 10 seconds to load into the QTableView. From what I can tell, the database returns results in only about a half a second longer, and it's the model(s) that is extremely slow. If I don't use the QSortFilterProxyModel, the data shows up in the table very quickly, but there's a 5 second or so lockup before I can scroll around the table or click on anything. Also, calling resizeColumnsToContents() on the tableview returns the lag of data appearance back to about 10 seconds. It should also be noted that I do not believe the SQL query itself is the issue here, because when I call the exact same query in Microsoft SQL Server Management Studio it returns instant results.

Questions:
1. Why the difference in speed? I know that the QODBC driver doesn't return a query size, is this the root of the problem?
2. If this is an inherent problem, is there a way around it? I know that people recommend setting setForwardOnly() on the query to true, but this is not allowed with a QSqlQueryModel and I didn't find that it dramatically increased speeds anyway - it is really such a small amount of data.

Of Note:
I didn't include any code because it didn't seem entirely necessary, but please let me know if it would help clarify anything and I can add it.