On Friday 19 December 2008 05:52:42 Simon Riggs wrote: > BTW, I noticed the other day that Oracle 11g only allows you to have a > read only slave *or* allows you to continue replaying. You need to > manually switch back and forth between those modes. They can't do > *both*, as Postgres will be able to do. That's because their undo > information is stored off-block in the Undo Tablespace, so is not > available for standby queries. Nice one, Postgres. >
I think this is true for physical replay, but Oracle also offers the option to do logical replay (where transaction logs are converted into sql and run against the standby; i believe this is similar to what continuant is trying to do with thier latest offering). In that scenario you can do read and replay at the same time, though I think there are some conflicts possible; fewer than what postgres will have, since I think most of thier DDL can be done online. (This might require some extra modules / high end version of Oracle, please consult your local Oracle wizard for more details) -- Robert Treat Conjecture: http://www.xzilla.net Consulting: http://www.omniti.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers