Qtsql qoci select query performance

[pateusz]

I've got a question performance of Qtsql module, exactly QOCI interface. Simple application which only connect and selects data, works way too slow (about 5 times) in comparison with other tools (sqldeveloper e.g). Low performance occurs on small, and big db tables.

Pseudo code looks as follows:
@QSqlDatabase db = QSqlDatabase::addDatabase("QOCI", "DB1");
db.setUserName("aaa");
db.setPassword("bbb");
db.setDatabaseName("aaa");
db.open();
QSqlQuery query(db);
query.setForwardOnly(true);
query.prepare("select x from y where rownum < 20");
query.setForwardOnly(true);
db.transaction();
query.exec();

while (query.next()) {
qDebug() << query.value(0).toString();
}@

Any suggestions how to make it faster? ps. i'm using qt 4.8.4 and ora client 11.2