On Tue, Jan 3, 2017 at 6:23 AM, Jim Nasby <Jim.Nasby@bluetreble.com> wrote: > + /* Check if wal_segment_size is in the power of 2 */ > + for (i = 0;; i++, pow2 = pow(2, i)) > + if (pow2 >= wal_segment_size) > + break; > + > + if (wal_segment_size != 1 && pow2 > wal_segment_size) > + { > + fprintf(stderr, _("%s: WAL segment size must be in the power of 2\n"), progname); > + exit(1); > + }
I recall taht pow(x, 2) and x * x result usually in the same assembly code, but pow() can never be more optimal than a simple multiplication. So I'd think that it is wiser to avoid it in this code path. Documentation is missing for the new replication command SHOW_WAL_SEG.
As mentioned earlier, documents are not fully updated.
Actually, why not just having an equivalent of the SQL command and be able to query parameter values?
This patch only needed the wal_segment_size and hence I made this specific command.
How often and why would we need other parameter values in the replication connection?
Making it a more general command to fetch any parameter can be a separate topic. If it gets consensus, maybe it could be done and used here.