Heikki Linnakangas <heikki.linnakangas@enterprisedb.com> writes:
> I was going to say that since we flush the WAL every 16MB anyway (at
> every XLOG file switch), you shouldn't see any benefit with larger ring
> buffers, since to fill 16MB of data you're not going to write more than
> 16MB WAL.
I'm not convinced that WAL segment boundaries are particularly relevant
to this. The unit of flushing is an 8K page, not a segment.
I wonder though whether the wal_buffers setting interacts with the
ring size. Has everyone who's tested this used the same 16MB
wal_buffers setting as in Alan's original scenario?
regards, tom lane