Horton

Re: foreign key locks, 2nd attempt

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Simon Riggs <simon@2ndQuadrant.com>
Cc: Alvaro Herrera <alvherre@alvh.no-ip.org>, Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2011-11-19T15:36:48Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Try to avoid running with a full fsync request queue.

Simon Riggs <simon@2ndQuadrant.com> writes:
> On Thu, Nov 3, 2011 at 6:12 PM, Alvaro Herrera <alvherre@alvh.no-ip.org> wrote:
>> So Noah Misch proposed using the FOR KEY SHARE syntax, and that's what I
>> have implemented here. (There was some discussion that instead of
>> inventing new SQL syntax we could pass the necessary lock mode
>> internally in the ri_triggers code. That can still be done of course,
>> though I haven't done so in the current version of the patch.)

> FKs are a good short hand, but they aren't the only constraint people
> implement. It can often be necessary to write triggers to enforce
> complex constraints. So user triggers need access to the same
> facilities that ri triggers uses. Please keep the syntax.

It's already the case that RI triggers require access to special
executor features that are not accessible at the SQL level.  I don't
think the above argument is a compelling reason for exposing more
such features at the SQL level.  All we need is that C-coded functions
can get at them somehow.

			regards, tom lane