Re: Holdable cursors in Oracle?

DA Morgan wrote:

> The Teradata architecuture is one where while a cursor is reading a table
> ... suppose someone comes along and wants the same data. Rather than
> opening a second cursor with associated parsing, overhead, etc. Teradata
> starts delivering records from the existing cursor to both sessions ...
> and when the first user gets what they want ... the cursors just keeps
> going with the records the second person requested. It is very efficient.

Within an OLAP context, yes.

I do not think the parsing is such a huge overhead myself. I'm using a scripting engine for a speech interface application I write. To parse and compile a script (containing the event handlers for the speech recognition engine) is usually just a few ms. And that is a way lot bigger than any huge and complex and nested SQL statement for a cursor. :-)

What can be expensive is building and maintaining state data. In an OLAP environment, there's less state data to maintain in comparison with OLTP.

So yeah, Teradata can likely get away with a feature like that... but personally I'm very hesitant in thinking that a similar feature will be of any real benefit in Oracle. If state data is an issue in something like Teradata, requiring globally shared cursors... that IMO points to an attempt to overcome limitations in design and not providing real froody features for developers and users.

--
Billy