From: Thomas J. Kyte Subject: Re: Oracle Parallel Server and 24x7 availability Date: 2000/06/06 Message-ID: <8hjhi0$egk$1@nnrp1.deja.com>#1/1 References: <_C8_4.231578$Tn4.2063175@news1.rdc2.pa.home.com> <960305947.21689.0.nnrp-09.9e984b29@news.demon.co.uk> X-Http-Proxy: 1.0 x55.deja.com:80 (Squid/1.1.22) for client 205.227.43.15 Organization: Deja.com - Before you buy. X-Article-Creation-Date: Tue Jun 06 18:57:13 2000 GMT X-MyDeja-Info: XMYDJUIDtkyte Newsgroups: comp.databases.oracle.server X-Http-User-Agent: Mozilla/4.0 (compatible; MSIE 5.01; Windows NT 5.0) In article <960305947.21689.0.nnrp-09.9e984b29@news.demon.co.uk>, "Jonathan Lewis" wrote: > > You are thinking of 'cache fusion'. > This is a feature to reduce pinging due > to read/write contention, not write/write. > > Oracle has implemented a 'consistent read > server', so that if node A want to read a block > that has recently been updated (and not written) > by node B then node B will create a consistent > read image of that block and pass it down the > interconnect rather than writing the block, and > the associated rollback segment header and > rollback blocks that node A would need to > create a CR image for itself. > > It node A want to write to the block, node B > still has to ping it down. > > -- > > Jonathan Lewis > Yet another Oracle-related web site: http://www.jlcomp.demon.co.uk > Jonathan -- I think Bob was referring to a new 8.1.6 configuration option of OPS for high availability... This is known as "Basic High Availability Configuration" or "Primary and Secondary Instances". See http://technet.oracle.com/doc/oracle8i_816/paraserv.816/a76968/pshavdtl. htm#10876 and http://technet.oracle.com/doc/oracle8i_816/paraserv.816/a76934/chap5.htm #1023930 for more info. It optimizes OPS to run in a 2 node environment where one node "reads" and the other "reads and writes" and further reduces pinging/inter node issues... It doesn't necessarily add to scaling in this configuration, only availability. (welcome back, haven't seen you on the group for a while...) > Bob Fazio wrote in message > <_C8_4.231578$Tn4.2063175@news1.rdc2.pa.home.com>... > >This will be short and sweet. > > > >I use it. I like it. I would recommend it. Raw devices aren't that hard, > >infact I prefer them. It's not what is advertised, but it's still worth it. > >In oltp enviroments you will want to be cautious, although I read that 8.1.6 > >does have mode that eliminates the problem with pinging that can occur in > >oltp enviroments. > > > > -- Thomas Kyte (tkyte@us.oracle.com) Oracle Service Industries Howtos and such: http://osi.oracle.com/~tkyte/index.html Oracle Magazine: http://www.oracle.com/oramag Opinions are mine and do not necessarily reflect those of Oracle Corp Sent via Deja.com http://www.deja.com/ Before you buy.