Re: join from array or cursor

On Sun, Aug 23, 2009 at 1:30 AM, John DeSoi<desoi(at)pgedit(dot)com> wrote:
> While it avoids the sort of my method, it appears to be almost 5 times
> slower (about 4000 keys in the cursor, Postgres 8.4.0):
>
>
> Function Scan on cursor_pk arr  (cost=0.00..116011.72 rows=1000 width=4)
> (actual time=13.561..249.916 rows=4308 loops=1)
>  SubPlan 1
>  SubPlan 2
>  SubPlan 3
> ...

Ugh, I guess using a subquery didn't work around the problem of the
(r).* getting expanded into multiple columns. This is starting to be a
more annoying limitation than I realized.

This also means when we do things like

select (x).* from (select bt_page_items(...))

or

select (h).* from (select heap_page_items(...))

It's actually calling bt_page_items() repeatedly, once for every
column in the output record? Bleagh.

--
greg
http://mit.edu/~gsstark/resume.pdf