From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
---|---|
To: | Alvaro Herrera <alvherre(at)commandprompt(dot)com> |
Cc: | Gregory Stark <stark(at)enterprisedb(dot)com>, Manoel Henrique <mhenriquesgbd(at)gmail(dot)com>, pgsql-hackers(at)postgresql(dot)org |
Subject: | Re: Research/Implementation of Nested Loop Join optimization |
Date: | 2008-07-26 00:44:49 |
Message-ID: | 4383.1217033089@sss.pgh.pa.us |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
Alvaro Herrera <alvherre(at)commandprompt(dot)com> writes:
> Tom Lane escribi:
>> Good joke, but to be serious: we expect that forward scans will result
>> in the kernel doing read-ahead, which will allow overlapping of
>> CPU work to process one page with the I/O to bring in the next page.
> I wonder if this is spoiled (or rather, the backwards case fixed) by the
> attempts to call posix_fadvise() on certain types of scan.
Yeah, I started wondering about that too after sending off the above.
The fadvise patch might eliminate the distinction ... on platforms where
fadvise exists and actually works well.
regards, tom lane
From | Date | Subject | |
---|---|---|---|
Next Message | Alvaro Herrera | 2008-07-26 02:36:43 | Re: Review: DTrace probes (merged version) ver_03 |
Previous Message | Alvaro Herrera | 2008-07-26 00:37:25 | Re: Research/Implementation of Nested Loop Join optimization |