Re: Oracle Parallel Server and 24x7 availability

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

Bob Fazio wrote in message
<_C8_4.231578$Tn4.2063175_at_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.

>