Re: PATCH: Reducing lock strength of trigger and foreign key DDL

From: Andreas Karlsson <andreas(at)proxel(dot)se>
To: Noah Misch <noah(at)leadboat(dot)com>, Andres Freund <andres(at)2ndquadrant(dot)com>
Cc: Michael Paquier <michael(dot)paquier(at)gmail(dot)com>, Robert Haas <robertmhaas(at)gmail(dot)com>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: PATCH: Reducing lock strength of trigger and foreign key DDL
Date: 2015-01-22 21:31:44
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On 01/20/2015 10:08 AM, Noah Misch wrote:
> Fair enough. It did reinforce pg_get_constraintdef() as a subroutine of
> pg_dump rather than an independent, rigorous interface. It perhaps made the
> function worse for non-pg_dump callers. In that vein, each one of these hacks
> has a cost. One could make a reasonable argument that ALTER TRIGGER RENAME
> locking is not important enough to justify spreading the hack from
> pg_get_constraintdef() to pg_get_triggerdef(). Lowering the CREATE TRIGGER
> lock level does not require any ruleutils.c change for the benefit of pg_dump,
> because pg_dump won't see the pg_trigger row of a too-recent trigger.

I agree with this view, and am not sure myself that it is worth lowering
the lock level of ALTER TRIGGER RENAME. I have attached a patch without
the changes to ALTER TRIGGER and ruleutils.c and also fixes the comment
issues noted by Andres.

Andreas Karlsson

Attachment Content-Type Size
add-fk-lock-strength-v5.patch text/x-patch 89.2 KB

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