Re: wal_buffers

Robert Haas <robertmhaas@gmail.com> writes:
> On Sun, Feb 19, 2012 at 9:46 AM, Euler Taveira de Oliveira
> <euler@timbira.com> wrote:
>> Isn't it useful to print some messages on the log when we have "wrap around"?
>> In this case, we have an idea that wal_buffers needs to be increased.

> I was thinking about that.  I think that what might be more useful
> than a log message is a counter somewhere in shared memory.  Logging
> imposes a lot of overhead, which is exactly what we don't want here,
> and the volume might be quite high on a system that is bumping up
> against this problem.  Of course then the question is... how would we
> expose the counter value?

Why do you need a counter, other than the current LSN?  Surely the
number of WAL buffer ring cycles can be deduced directly from that.
        regards, tom lane