On Thu, 2005-03-17 at 12:40 +0900, Satoshi Nagayasu wrote: > Tom Lane wrote: > >>I saw Oracle's reference manual, and found ALTER DATABASE OPEN READ ONLY > >>command > >>to make a stand-by database. > > > > Perhaps, but that's *not* what the TODO item is about. > > I see. > > Thanks for comments.
The Oracle ALTER DATABASE command is part of the multi-step process to mount an Oracle database into a running instance. It isn't something that you can dip in and out of when you choose, as far as I am aware: you can only run it on a warm standby database that is receiving logs shipped from another database. i.e. Oracle warm-standby databases have 3 run states (ok, more, but...) 1. warm standby 2. read-only 3. fully-operational You can switch between 1 and 2 and back again, but once you go to 3 then you cannot switch back. What Tom just proposed about having an additional run-state between running-recovery and fully-operational is essentially the same thing. Tom's overall strategy would be workable in PostgreSQL terms, with some work and would provide similar functionality to Oracle. Having said that, I believe we're not close to making that work just yet - its a good end goal because there may be choices along the way that may need to consider the longer term goal. Best Regards, Simon Riggs ---------------------------(end of broadcast)--------------------------- TIP 8: explain analyze is your friend
