Re: max_standby_delay considered harmful

Robert Haas <robertmhaas@gmail.com>

From: Robert Haas <robertmhaas@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Simon Riggs <simon@2ndquadrant.com>, pgsql-hackers@postgresql.org
Date: 2010-05-06T15:38:18Z
Lists: pgsql-hackers
On Mon, May 3, 2010 at 11:37 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> I'm inclined to think that we should throw away all this logic and just
> have the slave cancel competing queries if the replay process waits
> more than max_standby_delay seconds to acquire a lock.  This is simple,
> understandable, and behaves the same whether we're reading live data or
> not.

Now that I've realized what the real problem is with max_standby_delay
(namely, that inactivity on the master can use up the delay), I think
we should do what Tom originally suggested here.  It's not as good as
a really working max_standby_delay, but we're not going to have that
for 9.0, and it's clearly better than a boolean.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise Postgres Company