Re: pgsql: More cleanup after failed reduced-lock-levels-for-DDL feature.

From: Simon Riggs <simon(at)2ndQuadrant(dot)com>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: pgsql-committers <pgsql-committers(at)postgresql(dot)org>
Subject: Re: pgsql: More cleanup after failed reduced-lock-levels-for-DDL feature.
Date: 2011-10-22 12:27:06
Message-ID: CA+U5nMLqf+W8+_qm==a9V_NREJJm7NeifZDAwv=8PK2EQG2XFw@mail.gmail.com
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On Fri, Oct 21, 2011 at 6:50 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> More cleanup after failed reduced-lock-levels-for-DDL feature.
>
> Turns out that use of ShareUpdateExclusiveLock or ShareRowExclusiveLock
> to protect DDL changes had gotten copied into several places that were
> not touched by either of Simon's original patches for the feature, and
> thus neither he nor I thought to revert them.  (Indeed, it appears that
> two of these uses were committed *after* the reversion, which just goes
> to show that git merging is no panacea.)  Change these places to use
> AccessExclusiveLock again.  If we ever manage to resurrect that feature,
> we're going to have to think a bit harder about how to keep lock level
> usage in sync for DDL operations that aren't within the AlterTable
> infrastructure.
>
> Two of these bugs are only in HEAD, but one is in the 9.1 branch too.
> Alvaro found one of them, I found the other two.

Very cool, thanks.

--
 Simon Riggs                   http://www.2ndQuadrant.com/
 PostgreSQL Development, 24x7 Support, Training & Services

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