> 2. With sync replication, you have coordination problems and
> therefore it is never (at least IME) a win compared to master-slave
> replication since all writes must occur in the same order in the set,
> or you need global sequences, or such.
*snip*
> You will never get better read or write throughput,
Better read throughput is trivial to achieve even with other solutions
than multi-master replication.
And for better write throughput, the developers of Postgres-XC
(supported by NTT, among others) beg to differ:
http://postgresxc.wikia.com/wiki/Postgres-XC_Wiki
http://postgres-xc.sourceforge.net/
As does Bettina Kemme (of Postgres-R fame).
Sincerely,
Wolfgang