| From: | "Kevin Grittner" <Kevin(dot)Grittner(at)wicourts(dot)gov> |
|---|---|
| To: | "Andrew Dunstan" <andrew(at)dunslane(dot)net>, "Tom Lane" <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
| Cc: | "Greg Smith" <greg(at)2ndquadrant(dot)com>, "Heikki Linnakangas" <heikki(dot)linnakangas(at)enterprisedb(dot)com>, "Robert Haas" <robertmhaas(at)gmail(dot)com>, "Joachim Wieland" <joe(at)mcknight(dot)de>, "pgsql-hackers" <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: WIP patch for parallel pg_dump |
| Date: | 2010-12-06 18:11:18 |
| Message-ID: | 4CFCD2E60200002500038351@gw.wicourts.gov |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> I'm still not convinced that using shared memory is a bad way to
>> pass these around. Surely we're not talking about large numbers
>> of them. What am I missing here?
>
> They're not of a very predictable size.
Surely you can predict that any snapshot is no larger than a fairly
small fixed portion plus sizeof(TransactionId) * MaxBackends? So,
for example, if you're configured for 100 connections, you'd be
limited to something under 1kB, maximum?
-Kevin
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Tom Lane | 2010-12-06 18:15:47 | Re: serializable read only deferrable |
| Previous Message | Pavel Stehule | 2010-12-06 18:10:12 | Re: Per-column collation |