OK, updated:
<P>Though "replication" is a single term, there are several technologies
for doing replication, with advantages and disadvantages for each.</P>
<P>Master/slave replication allows a single master to receive read/write
queries, while slaves can only accept read/<SMALL>SELECT</SMALL> queries.
The most popular freely available master-slave PostgreSQL replication
solution is <A href="http://gborg.postgresql.org/project/slony1/projdisplay$
Slony-I</A>.</P>
<P>Multi-master replication allows read/write queries to be sent to
multiple replicated computers. This capability also has a severe
impact on performance due to the need to synchronize changes between
servers. <A href="http://pgfoundry.org/projects/pgcluster/";>Pgcluster</a>
is the most popular such solution freely available for PostgreSQL.</P>
<P>There are also commercial and hardware-based replication solutions
available supporting a variety of replication models.</P>
---------------------------------------------------------------------------
Christopher Browne wrote:
> Martha Stewart called it a Good Thing when [email protected] (Bruce
> Momjian) wrote:
> > Yep, big mistake my removing the replication FAQ item. I have re-added a
> > new one:
> >
> > 4.21) What replication solutions are available?
> >
> > Though "replication" is a single term, there are two major replication
> > technologies. Multi-master replication allows read/write queries to be
> > sent to multiple replicated computers. Using this capability has a
> > serious performance impact. Pgcluster is the most popular such solution
> > available for PostgreSQL. Master-slave replication allows a single
> > master to receive read/write queries, with slaves able to accept only
> > read/SELECT queries. The most popular master-slave PostgreSQL
> > replication solution is Slony. There are also commercial and
> > hardware-based replication solutions available.
>
> A suggestion for rewording:
>
> Though "replication" is a single term, there are a number of
> approaches and technologies to handle it, and thus, for different
> purposes, a number of replication systems are available.
>
> Master/slave replication allows a single master to receive read/write
> queries, where slaves can only accept read/SELECT queries. The most
> popular freely available master-slave PostgreSQL replication solution
> is Slony-I.
>
> Multi-master replication allows read/write queries to be sent to
> multiple replicated computers. Using this capability generaly has a
> fairly severe impact on performance due to the need to synchronize
> changes between servers. Pgcluster is the most popular such solution
> freely available for PostgreSQL.
>
> There are also commercial and hardware-based replication solutions
> available supporting a variety of replication models.
> --
> (format nil "[EMAIL PROTECTED]" "cbbrowne" "acm.org")
> http://linuxdatabases.info/info/slony.html
> "It can be shown that for any nutty theory, beyond-the-fringe
> political view or strange religion there exists a proponent on the
> Net. The proof is left as an exercise for your kill-file."
> -- Bertil Jonell
>
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