Re: Pass thru queries WAS: Maximum OBDC Query Size

On Tue, Apr 9, 2019 at 11:27 AM John Yeung <gallium.arsenide@xxxxxxxxx>
wrote:

On Tue, Apr 9, 2019 at 12:01 PM Charles Wilt <charles.wilt@xxxxxxxxx>
wrote:

I think most RDBMS type applications offer the option for a "pass through
query" when connecting to an RDBMS of a different vendor.

OK. I stand corrected.

But I am not used to the idea of connecting to a database... FROM a
database. That is, it doesn't occur to me that I would be in the
situation that I would be writing SQL *in* Db2 or Oracle or whatever,
and be connecting to some *other* database. That's just a totally
foreign architecture to me.

You're lucky ;)

Most shops have more than one brand of RDBMS...

And at some point, an app needs data from more than one RDBMS.

Thus the whole concept of "DB Federation"

It's much easier for the application to connect to a single DB and let that
DB handle getting the data from another DB as needed.

Downside of course is you lose DB unique functionality, which is where
"pass through SQL" comes into play.

Charles