Not exactly the same issue, but when we moved our application onto a Citrix farm separated from the database server by a Gig Ethernet, then some queries which had simply performed poorly when the were on PCs on a 10 meg Ethernet network suddenly had a significantly larger impact on the database. Obviously if the 2 databases are on separate servers there would be a throttling effect on queries that involved full table scans of large tables. However I suspect that there would be a more conventional way to achieve the same goal. Dave David Roberts www.logica.com Logica UK Limited Registered in England and Wales (registered number 947968) Registered office: Stephenson House, 75 Hampstead Road, London NW1 2PL, United Kingdom -----Original Message----- From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Brady, Mark Sent: 24 September 2008 16:07 To: oracle-l Subject: two instance -- one database I have a friend (no really, this isn't some lame way of telling you about me but trying to hide that by ... ) I have a friend, and at his company they have an Oracle database with tables and data. We'll call it Database A and they have another Database B that has views across dblinks to each of the tables in Database A. The data team says that this protects Database A from bad queries. So can anyone think of any possible benefit from this arrangement? Will administration be easier, queries faster, performance more predictable? Anything? >>> This e-mail and any attachments are confidential, may contain legal, professional or other privileged information, and are intended solely for the addressee. If you are not the intended recipient, do not use the information in this e-mail in any way, delete this e-mail and notify the sender. CEG-IP1 This e-mail and any attachment is for authorised use by the intended recipient(s) only. It may contain proprietary material, confidential information and/or be subject to legal privilege. It should not be copied, disclosed to, retained or used by, any other party. If you are not an intended recipient then please promptly delete this e-mail and any attachment and all copies and inform the sender. Thank you.