| From: | Dean Rasheed <dean(dot)a(dot)rasheed(at)gmail(dot)com> |
|---|---|
| To: | Robert Haas <robertmhaas(at)gmail(dot)com> |
| Cc: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, PostgreSQL Hackers <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: Index-only scan performance regression |
| Date: | 2012-02-02 09:39:41 |
| Message-ID: | CAEZATCUD7xMbm8eEKUdV5=J2kSk7BALfvBODDxKssCWB3mGDjw@mail.gmail.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On 2 February 2012 01:40, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
> On Wed, Feb 1, 2012 at 7:44 PM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
>> So, I guess the trade-off here is that, since sinval messages aren't
>> processed immediately, we often won't notice the VM extension until
>> the next statement starts, whereas with the current implementation, we
>> notice it right away. On the other hand, noticing it right away is
>> costing us a system call or two per tuple. So on further thought, I
>> think we should do this.
>
Yes, that's a nice summary.
> Patch committed. I moved the smgr inval to after the actual extension
> is done, which seems superior, and adjusted the comments slightly.
>
Thanks.
Regards,
Dean
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Heikki Linnakangas | 2012-02-02 09:47:43 | Re: Refactoring log_newpage |
| Previous Message | Abhijit Menon-Sen | 2012-02-02 09:35:55 | Re: JSON output functions. |