Date: Thu, 25 May 2017 18:19:53 -0700 (MST)
From: y39chen <yan-jack.chen@nokia.com>
To: pgsql-general@postgresql.org
Message-ID: <1495761593082-5963349.post@n3.nabble.com>
In-Reply-To: <15664.1495720075@sss.pgh.pa.us>
References: <1495609157661-5963011.post@n3.nabble.com>
 <2253.1495639128@sss.pgh.pa.us>
 <CAB7nPqRLBA9vxT+o2_JOThKzHGbGpmZyTbJBRR1jW5QKq+NeYQ@mail.gmail.com>
 <2353.1495640833@sss.pgh.pa.us>
 <CAB7nPqT3S_wG3J3GXeaXDgeS1sdwgz52F=Ze+uBbrWX89EO4wQ@mail.gmail.com>
 <1495704189413-5963181.post@n3.nabble.com> <15664.1495720075@sss.pgh.pa.us>
Subject: Re: Is there possibility btree_redo with XLOG_BTREE_DELETE done
 between standby_redo and the end of backup
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Precedence: bulk
Sender: pgsql-general-owner@postgresql.org

Yeah, I figured out the point(logic). The precondition is should not have any
connections accept while recovering. It is clear to me now. Thank you very
much.

static TransactionId
btree_xlog_delete_get_latestRemovedXid(xl_btree_delete *xlrec)
{
......
	if (*CountDBBackends(InvalidOid)* == 0)
		return latestRemovedXid;

	/*
	 * In what follows, we have to examine the previous state of the index
	 * page, as well as the heap page(s) it points to.  This is only valid if
	 * WAL replay has reached a consistent database state; which means that
	 * the preceding check is not just an optimization, but is *necessary*. We
	 * won't have let in any user sessions before we reach consistency.
	 */
	if (!reachedConsistency)
            elog(PANIC, "btree_xlog_delete_get_latestRemovedXid: cannot
operate with inconsistent data");

......
}


--
View this message in context: http://www.postgresql-archive.org/Is-there-possibility-btree-redo-with-XLOG-BTREE-DELETE-done-between-standby-redo-and-the-end-of-backp-tp5963066p5963349.html
Sent from the PostgreSQL - general mailing list archive at Nabble.com.


-- 
Sent via pgsql-general mailing list (pgsql-general@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-general