Re: Assertion failure on hot standby - Mailing list pgsql-hackers

From Andres Freund
Subject Re: Assertion failure on hot standby
Date
Msg-id 201011261341.59331.andres@anarazel.de
Whole thread Raw
In response to Re: Assertion failure on hot standby  (Robert Haas <robertmhaas@gmail.com>)
Responses Re: Assertion failure on hot standby
List pgsql-hackers
On Friday 26 November 2010 13:32:18 Robert Haas wrote:
> On Fri, Nov 26, 2010 at 1:11 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> > Simon Riggs <simon@2ndQuadrant.com> writes:
> >> That would mean running GetCurrentTransactionId() inside LockAcquire()
> >> 
> >> if (lockmode >= AccessExclusiveLock &&
> >>     locktag->locktag_type == LOCKTAG_RELATION &&
> >>     !RecoveryInProgress())
> >>       (void) GetCurrentTransactionId();
> >> 
> >> Any objections to that fix?
> > 
> > Could we have a wal level test in there too please?  It's pretty awful
> > in any case...
> Incidentally, I haven't been able to wrap my head around why we need
> to propagate AccessExclusiveLocks to the standby in the first place.
> Can someone explain?
To make the standby stop applying WAL when a local transaction on the standby 
uses an object.
E.g. dropping a table on the master need the standby top stop applying wal (or 
kill the local client using the table).
How would you want to protect against something like that otherwise?

Andres


pgsql-hackers by date:

Previous
From: Robert Haas
Date:
Subject: Re: Assertion failure on hot standby
Next
From: Florian Pflug
Date:
Subject: Re: improving foreign key locks