| From: | Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> |
|---|---|
| To: | Heikki Linnakangas <hlinnakangas(at)vmware(dot)com> |
| Cc: | Rajeev rastogi <rajeev(dot)rastogi(at)huawei(dot)com>, Ants Aasma <ants(at)cybertec(dot)at>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>, Markus Wanner <markus(at)bluegap(dot)ch> |
| Subject: | Re: Proposal for CSN based snapshots |
| Date: | 2014-05-14 03:40:55 |
| Message-ID: | CAA4eK1J0NARhmY59bMcs79g-LEYHAnst4B6NOi7QYVtXyw0WmQ@mail.gmail.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On Tue, May 13, 2014 at 1:59 PM, Heikki Linnakangas
<hlinnakangas(at)vmware(dot)com> wrote:
> On 05/13/2014 09:44 AM, Amit Kapila wrote:
>>
>> To accomplish this won't XID-CSN map table be required and how will
>> it be maintained (means when to clear and add a entry to that map table)?
>
>
> Not sure I understand. The clog is a mapping from XID to CSN.
The case I was referring is for xmin < XID < xmax, which you have
mentioned below that you are planing to directly refer pg_clog. This
is I think one of the main place where new design can have impact
on performance, but as you said it is better to first do the implementation
based on pg_clog rather than directly jumping to optimize by maintaining
XID to CSN mapping.
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Tom Lane | 2014-05-14 03:42:51 | Re: gettimeofday is at the end of its usefulness? |
| Previous Message | Sergey Muraviov | 2014-05-14 03:40:03 | Typo in release notes |