Dennis, I don't see a problem with combining instances, at the start. But as you state a single company may desire to upgrade & if their all bound into one schema separating them is going to be a real pain. Moving a schema is fairly easy. ........................................................................ ............................................................. Kanbay <http://www.kanbay.com/> Dick Goulet, Senior Oracle DBA 45 Bartlett ST | Marlborough, MA 01752 USA Tel: 508.573.1978 | Fax: 508.229.2019 | Cell: 508.742.5795 rgoulet@xxxxxxxxxx <mailto:rgoulet@xxxxxxxxxx> ........................................................................ ............................................................. ________________________________ From: Dennis Williams [mailto:oracledba.williams@xxxxxxxxx] Sent: Thursday, May 03, 2007 4:33 PM To: Richard J. Goulet Cc: jg_dba@xxxxxxxxx; oracle-l@xxxxxxxxxxxxx Subject: Re: RAC 10G for different companies with one shared database and label security Joop, I agree with Richard. Can you explain a little more about why you desire to combine instances? It seems to me that the ERP system might not be designed for what you desire. Also, if one company needs to upgrade to a new version of the ERP software, but other companies don't want to upgrade yet then you must force all them to work out a compromise. I run into that between corporate divisions, and it isn't pleasant. I would imagine that between independent companies it could get painful. Dennis Williams