From: | Jeff Davis <pgsql(at)j-davis(dot)com> |
---|---|
To: | pgsql-general(at)postgresql(dot)org |
Subject: | return next |
Date: | 2005-11-11 08:25:32 |
Message-ID: | 4374557C.9070005@j-davis.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-general |
I'm attempting to make a table function that starts returning to the
client before the entire result set is constructed.
From the docs on plperl:
"Usually you'll want to return rows one at a time, both to speed up
startup time and to keep from queueing up the entire result set in
memory. You can do this with return_next as illustrated below."
However, when I do a simple plperl function:
create or replace function itab(int) returns setof int as $$
for (0..$_[0]-1) {
return_next $_;
}
return undef;
$$ language plperlu;
It seems to always try to build the entire result first. For example, if
I put a "sleep 1" in the loop and do "select * from itab(10) limit 1" it
takes 10 seconds rather than 1 second. Same if I use a cursor and just
fetch one.
Am I misunderstanding the docs? How do I just return one tuple at a time
without PostgreSQL continuing the loop?
I'm using PostgreSQL 8.1.
Regards,
Jeff Davis
From | Date | Subject | |
---|---|---|---|
Next Message | Peter Eisentraut | 2005-11-11 08:32:38 | Re: Best way to use indexes for partial match at |
Previous Message | Richard Huxton | 2005-11-11 08:08:01 | Re: run vacuum from within a function |