Re: Avoiding adjacent checkpoint records

Simon Riggs <simon@2ndQuadrant.com> writes:
>> Robert Haas <robertmhaas@gmail.com> wrote:
>>> I know of real customers who would have suffered real data loss
>>> had this code been present in the server version they were using.

> If that is the concern, then its a one line fix to add the missing clog flush.

To where, and what performance impact will that have?

> The other suggestions I've skim read seem fairly invasive at this
> stage of the release.

The issue here is that we committed a not-very-well-thought-out fix
to the original problem.  I think a reasonable argument could be made
for simply reverting commit 18fb9d8d21a28caddb72c7ffbdd7b96d52ff9724
and postponing any of these other ideas to 9.3.  The useless-checkpoints
problem has been there since 9.0 and can surely wait another release
cycle to get fixed.  But I concur with Robert that changing the system
behavior so that checkpointing of committed changes might be delayed
indefinitely is a high-risk choice.
        regards, tom lane