Hi Cheng I mean a patch that is certified as a rolling upgarde patch that needs to be applied on both the nodes. regards Hrishy --- On Thu, 2/7/09, LS Cheng <exriscer@xxxxxxxxx> wrote: From: LS Cheng <exriscer@xxxxxxxxx> Subject: Re: Rolling upgrades and client connection To: hrishys@xxxxxxxxxxx Cc: oracle-l@xxxxxxxxxxxxx Date: Thursday, 2 July, 2009, 10:47 AM I dont understand very well the question, do you mean apply an one-off as hot patch online? Thanks -- LSC On Thu, Jul 2, 2009 at 10:53 AM, hrishy <hrishys@xxxxxxxxxxx> wrote: Hi I have a question on rolling upgrades of 2 node RAC databases. I understand while performing a rolling upgrade i need to stage the patch to a directory and just launch Opatch from that directory and Opatch would roll over the patch to the remote node and apply it there . My question is what happens to the existing and new user connections as the database is not stopped what happens when the patch is being applied to node 1 a)Users are already connectted to node 1 b) new users connection who are attempting to connect to node 1 regards Hrishy