Does JDBC have an equivalent to the ADO GetRows method?

Question

In ADO you can retreive multiple rows at a time use the GetRows method. Is there any way with JDBC to retrieve multiple rows at a time?

Answer 1

Well, the exact specifics of how the driver works are a little beyond my vision, but here's how I understand it. A stream is like a pipeline. When you make the query the databases begins pushing rows onto the pipeline at a predetermined rate (ie. n at a time).
As long as you keep reading them with next(), the database keeps pushing more on until there are none left, or until you stop reading them. I think this is the premise behind the traditional database cursor as well. You didn't get the million, you got the first few of the million.
The efficiency comes because if you get what you need after say twelve rows, you stop calling next. Without calling next, the database stops pushing more "reads" into the pipeline (or stream). This is why its nice to close the result set if you are done with it... it tells the database to stop sitting there waiting to push more rows along the stream.
ADO does force the database to read all million. JDBC starts reading the million, and if you're done after twelve then the database only read twelve ...plus a few extra left on the stream ... but certainly nowhere near the whole million. Make sense? This is why Oracle, for instance, cannot tell you how many rows are held in a table unless you force it using the count aggregate. Oracle says "if you wanna know ...count em yourself!"
I hope I have the concepts right here... anyone else is welcome to add their input.
GumB.