Jeff Frost wrote: > On Tue, 14 Nov 2006, Bruce Momjian wrote: > > > Your description was too detailed, but I took some of your concepts: > > > > <para> > > In clustering, each server can accept write requests, and these > > write requests are broadcast from the original server to all > > other servers before each transaction commits. Heavy write > > activity can cause excessive locking, leading to poor performance. > > In fact, write performance is often worse than that of a single > > server. Read requests can be sent to any server. Clustering > > is best for mostly read workloads, though its big advantage is > > that any server can accept write requests --- there is no need > > to partition workloads between read/write and read-only servers. > > </para> > > > > <para> > > Clustering is implemented by <productname>Oracle</> in their > > <productname><acronym>RAC</></> product. <productname>PostgreSQL</> > > does not offer this type of load balancing, though > > <productname>PostgreSQL</> two-phase commit (<xref > > linkend="sql-prepare-transaction-title"> and <xref linkend= > > "sql-commit-prepared-title">) can be used to implement this in > > application code or middleware. > > </para> > > Bruce, > > Continuent's uni/cluster middleware product implements this type of > clustering/load balancing. Perhaps it warrants a mention? Not sure how far > we want to get into listing external products.
We had a long discussion about that and felt that recommending commercial products or even every open source project was too much. The idea was that we should reference a web page that has them all mentioned, but no one has set one up yet. -- Bruce Momjian [EMAIL PROTECTED] EnterpriseDB http://www.enterprisedb.com + If your life is a hard drive, Christ can be your backup. + ---------------------------(end of broadcast)--------------------------- TIP 5: don't forget to increase your free space map settings
