I have been told that SQL Native Client is supposed to be faster than the OLEDB drivers. So I put together a utility to do a load-test between the two – and am getting mixed results. Sometimes one is faster, sometimes the other is, no matter what the query may be (simple select, where clause, joining, order by, etc.). Of course the server does the majority of the workload, but I’m interested in the time it takes between the data coming into the PC to the time the data is accessible within the app.
The load tests consist of very small queries which return very large datasets. For example, I do select * from SysTables and this table has 50,000+ records. After receiving the data, I do another load of looping through the results (using while not Q.eof ... Q.next ... etc.). I’ve also tried adding some things to the query – such as order by Val where Val is a varchar(100) field.
Here’s a sample of my load tester, numbers on very bottom are averages…

So really, what are the differences between the two? I do know that OLE is very flexible and supports many different database engines, whereas Native Client is specific to SQL Server alone. But what else is going on behind the scenes? And how does that affect how Delphi uses these drivers?
This is specifically using ADO via the TADOConnection component and TADOQuery as well.
I’m not necessarily looking or asking for ways to improve performance – I just need to know what are the differences between the drivers.
As stated by Microsoft:
From my understanding, ADO is just an Object Oriented application-level DB layer over OleDB. It will use OleDB in all cases. What changes is the provider used. If you specify the
SQLNCLI10provider, you’ll use the latest version of the protocol. If you specify theSQLOLEDBprovider, you’ll use the generic SQL Server 2000 + protocol.As such:
About performance, I think you won’t have a big difference. Like always, it will depend on the data processed.
But it is IMHO recommended to use best fitted provider for your database. Some kind of data (like
var(maxchar)orInt64) is told to be best handled. And theSQLNCLI10provider has been updated, so I guess it is more tuned.