Re: How do I use the backend APIs

On Mon, 2006-02-20 at 16:40, Martijn van Oosterhout wrote:
> On Mon, Feb 20, 2006 at 05:08:33AM -0800, Chad wrote:
> > 4. Why I think I need to work at this level of abstraction. I believe,
> > certain types of queries can be realized more efficiently by code that
> > can seek to specific parts of an index and immediately returning a
> > small number of rows to the client. The query would remain active and
> > the client would only retrieve the next rows after the previous cursor
> > position when the client was ready to do so. With a huge underlying
>
> <snip>
>
> You realise you can acheive almost exactly what you want here by saying
> things like:
>
> DECLARE c AS CURSOR FOR select * from table where name >= 'Mal' order by name;
> FETCH FORWARD 1; -- Go down
> FETCH FORWARD 1; -- Go down
> FETCH BACKWARD 2; -- Go back again
>
> If you have an index it will just step through the index to find the
> rows you want. While you're free to try and make this work by using the
> index code directly, you're not asking anything that's otherwise
> impossible.

I think the problem here is that when you have a hammer, everything
looks like a nail. We see it with people coming from Oracle or DB2 as
well. "I learned it this way" is often a bigger obstacle to learning
postgresql than no knowledge at all.