From: | "Matthew Campbell" <mtthw(dot)cmpbll(at)gmail(dot)com> |
---|---|
To: | "Tom Lane" <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
Cc: | pgsql-novice(at)postgresql(dot)org |
Subject: | Re: Newbie Developer Question |
Date: | 2007-02-01 16:58:08 |
Message-ID: | c2cc277f0702010858q16e6ae21qfece5981e59c06af@mail.gmail.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-novice |
Thanks so much for the help. _hash_first, and _hash_next all take the scan
object as a parameter. How do you create or get a scan object?
hashbeginscan looks like it sets up a scan and returns it, but it takes the
number of keys and the array of scan keys. Where do we get these arguments
from?
-Matt
On 2/1/07, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>
> "Matthew Campbell" <mtthw(dot)cmpbll(at)gmail(dot)com> writes:
> > ... We've been digging through the src/backend/access/hash/
> > and we're having a hard time figuring out the correct way to walk
> through
> > items in a page. Is this what the hashbeginscan() method is for?
>
> No, hashbeginscan doesn't do much at all except initialize state. The
> interesting stuff happens during successive hashgettuple calls ---
> specifically _hash_first the first time and _hash_next on later calls.
>
> regards, tom lane
>
From | Date | Subject | |
---|---|---|---|
Next Message | ann hedley | 2007-02-01 17:01:14 | Re: query efficiency - Can I speed it up? |
Previous Message | Rob Shepherd | 2007-02-01 16:57:14 | Stored Procedure to return a result set |