MIRROR database questions

Hello all. I was reading an article by Rich Heiges called Mirroring - A New Look at HA. It left me with 2 questions

(A) Can I change the operating modes of the principal and mirror roles on the fly, or do I have to stop the MirROR process?

(B) It said that MIRROR supports 32-bit to 64-bit H/W interoperability -- but will it support interoperability between 32-bit and 64-bit instances of the database?

Thanks!

For (A), you meant role-swithing (i.e. making mirror the principal and vice-versa). You can do manual fail over but this requires you to suspend mirroring. Active transactions are rolled back but connection to the new principal are established automatically. And finally, you will need to re-establish mirroring.

For (B), I think the answer is yes, but it needs to be confirmed.

thanks

|||(A) yes you can change all operating modes on the fly.

(B) there is no such thing as a 32-bit or a 64-bit database. the file formats are exactly the same, only the in memory operations are different. of course, if you require 64 bit address space to satisfy your database performance needs, mirroring to a 32 bit box probably isn't going to be a good idea, because your performance will not be very good after a failover.

thanks,
mark|||Thanks for the answer. I get (B). To be clear on (A), I don't mean changing the roles of the principal, I meant changing the saftey level and protection levels on the fly, or do I have to stop the process and restrat with a different setting?

Of course, even if I stop MIRROR, I'll assume the database doesn't need to go down to make the change?

Thanks..|||Not sure if I messed up my reply post -- but I meant changing the mode of the operating, not the roles, on the fly. So changing the protection level without stopping the MIRROR process. But if I did need to stop it, I don't need to take a database outage, or do I?|||

you can change the protection levels without stopping. in previous versions of db mirroring, the June CTP and earlier, i think, changing the safety level, or operating mode caused the database to be restarted, which would close all connections. we have since fixed that.

|||Thanks - -but just to clarify you mean without stopping the database right? I have to break the MIRROR pair and they will perform catchup when I bring them back together? (I should have been more clear in the question - thanks)|||you should be able to change the SAFETY level without stopping the database mirroring session or the restarting the database itself.