From: Bruce Momjian <bruce@momjian.us>
Message-Id: <200711192121.lAJLLAi07431@momjian.us>
Subject: Re: High Availability, Load Balancing, and Replication Feature Matrix
In-Reply-To: <4741E93F.7090909@bluegap.ch>
To: Markus Schiltknecht <markus@bluegap.ch>
Date: Mon, 19 Nov 2007 16:21:10 -0500 (EST)
CC: PostgreSQL-documentation <pgsql-docs@postgresql.org>
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Markus Schiltknecht wrote:
> Eh.. I think you misunderstood. The Sequoia people use RAIDb to mean 
> Redundant Array of Inexpensive _Databases_. A possible setup might look 
> like:

You are right.  I didn't understand that.  Interesting.

> > I am afraid we are stuck between clarity and understand-ability here. ;-)
> 
> Agreed, but that's where I think the current chapter creates confusion 
> by trying to separate into "statement based replication middleware" and 
> "synchronous multi-master replication". Such a separation does not 
> exist, instead every combination of single vs. multi-master and 
> statement based vs tuple based is possible. Examples:
> 
> single-master, tuple based: Slony-I, Mammoth Replicator
> multi-master, tuple based: Postgres-R, Slony-II, maybe Bucardo (?)
> single-master, statement based: maybe pgpool or skytools can do that (?)
> multi-master, statement based: Sequoia, PgCluster

Uh, to me the issue is something like pgpool and Sequoia, where the
_master_/replication is happening _outside_ the server, vs something
like Oracle RAC where it is happening inside the server.

-- 
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://postgres.enterprisedb.com

  + If your life is a hard drive, Christ can be your backup. +