Oracle FAQ Your Portal to the Oracle Knowledge Grid

Home -> Community -> Mailing Lists -> Oracle-L -> Re: RAC gv$session

Re: RAC gv$session

From: Tim Gorman <>
Date: Thu, 11 Mar 2004 09:40:42 -0700
Message-ID: <>

SID and SERIAL# are not guarenteed unique across instances. INST_ID is the last part of that implied primary key, for all GV$ views. Look at V$FIXED_VIEW_DEFINITION The data for each instance, including memory-based V$ views like V$SESSION, is maintained solely within that instance. When necessary, those GV$ views are populated using cross-instance queries via parallel execution │slave▓ (i.e. │ora_pXXX_SID▓) processes. Exceptions include the V$ views that are based in the control file, such as V$DATABASE, V$THREAD, V$DATAFILE, etc. whose data is visible to all instances through the shared control files. At least, that is how it was done for 8/8i OPS ‹ I haven╣t verified whether 9i RAC has found something more clever involving cache fusion and the │block-shipping▓ processes or something. The GV$ views did not exist in Oracle7 and prior ‹ we had to write them custom. Can anyone confirm or correct about how 9iRAC displays GV$ info?

Still, although you can view SID and SERIAL# from across the cluster (though GV$ views), you can only utilize them in │DBMS_▓ package calls or from ALTER SYSTEM KILL SESSION, etc. from the appropriate instance...

on 3/11/04 7:48 AM, Kommareddy, Srinivas (MED, Wissen Infotech) at wrote:

> Hi All,
> We have 2 nodes set for RAC.
> When I try to kill a session from node 1, is the sid,serial# going to be
> unique among the nodes,
> Or is there any possibility that another session on node 2 will be killed (if
> sid, seiral# are same for another session on node 2).
> Does my select sid,serial# checks v$session or gv$session.
> Can someone through some light on this.
> Tx and Regards,
> Srinivas

Please see the official ORACLE-L FAQ:

To unsubscribe send email to: put 'unsubscribe' in the subject line.
Archives are at
FAQ is at
Received on Thu Mar 11 2004 - 11:18:35 CST

Original text of this message