Re: Skip checkpoint on promoting from streaming replication

On 8 June 2012 09:22, Kyotaro HORIGUCHI <horiguchi(dot)kyotaro(at)lab(dot)ntt(dot)co(dot)jp> wrote:

> I have a problem with promoting from hot-standby that exclusive
> checkpointing retards completion of promotion.

Agreed, we have that problem.

> I depend on this and suppose we can omit it if latest checkpoint
> has been taken so as to be able to do crash recovery thereafter.

I don't see any reason to special case this. If a checkpoint has no
work to do, then it will go very quickly. Why seek to speed it up even
further?

> This condition could be secured by my another patch for
> checkpoint_segments on standby.

More frequent checkpoints are very unlikely to secure a condition that
no checkpoint at all is required at failover.

Making a change that has a negative effect for everybody, in the hope
of sometimes improving performance for something that is already fast
doesn't seem a good trade off to me.

Regrettably, the line of thought explained here does not seem useful to me.

As you know, I was working on avoiding shutdown checkpoints completely
myself. You are welcome to work on the approach Fujii and I discussed.

--
 Simon Riggs                   http://www.2ndQuadrant.com/
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