From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
---|---|
To: | Robert Haas <robertmhaas(at)gmail(dot)com> |
Cc: | Andres Freund <andres(at)2ndquadrant(dot)com>, "pgsql-hackers(at)postgresql(dot)org" <pgsql-hackers(at)postgresql(dot)org> |
Subject: | Re: pg_shmem_allocations view |
Date: | 2014-05-05 19:09:02 |
Message-ID: | 20206.1399316942@sss.pgh.pa.us |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> On Sun, May 4, 2014 at 7:50 AM, Andres Freund <andres(at)2ndquadrant(dot)com> wrote:
>> Thinking about this, I think it was a mistake to not add a 'name' field
>> to dynamic shared memory's dsm_control_item.
> Well, right now a dsm_control_item is 8 bytes. If we add a name field
> of our usual 64 bytes, they'll each be 9 times bigger.
And the controlled shared segment is likely to be how big exactly? It's
probably not even possible for it to be smaller than a page size, 4K or
so depending on the OS. I agree with Andres that a name would be a good
idea; complaining about the space needed to hold it is penny-wise and
pound-foolish.
> I'm quite in favor of having something like this for the main shared
> memory segment, but I think that's 9.5 material at this point.
If you're prepared to break the current APIs later to add a name parameter
(which would have to be required, if it's to be useful at all), then sure,
put the question off till 9.5.
regards, tom lane
From | Date | Subject | |
---|---|---|---|
Next Message | Andres Freund | 2014-05-05 19:09:46 | Re: pg_shmem_allocations view |
Previous Message | Robert Haas | 2014-05-05 19:04:07 | Re: pg_shmem_allocations view |