Once I work at creating such environment that during possible downtimes applications used their cache entries until a database was available again :-), but this is not always possible. IMHO an application needs to be designed with possible db downtimes in mind W dniu 20.03.2012 07:36, Purav Chovatia pisze: > Hi, > We have a requirement to apply application patches online i.e. without > downtime. Our apps run in active-active mode and hence the app layer is > taken care of i.e. while instance-1 of app is being upgraded, the live > traffic is handled by instance-2. And once that is done, live traffic is > handled by instance-2 and instance-1 is upgraded. However the challenge is > to modify the DB objects i.e. SPs, tables, indices, etc. > > When I was given this requirement, initially I resisted. But later I > thought, may be this looks like a common problem with increasing demand of > high availability. So can you pls give me some guidance on how is this > requirement handled across the industry? What do you all do? > For e.g. if I have to modify a SP, I know that cannot be done while the > apps are accessing it. Is there some workaround? May be writing wrappers, > etc.? > Similarly for other changes like adding or dropping a column. > > I think Edition based Redifinition is a step towards it but a first glance > at it made me feel that its very complicated, still maturing, and does not > cover all types of changes. > > If anybody has some best practices that are being followed can you please > share? > > Thanks. > > > -- > //www.freelists.org/webpage/oracle-l > > > -- Pole nakazi ---------------------------------------------------------------------- Remigiusz Sokolowski <remigiusz.sokolowski@xxxxxxxxxx> pos : DBA at DIiUSI addr : Nordea Bank Polska SA, Luzycka 6A Street, 81-537 Gdynia, Poland phone : +48 58 667 17 43 mobile: +48 602 42 42 77 Nordea Bank Polska S.A. z siedziba w Gdyni, ul. Kielecka 2, 81-303 Gdynia, wpisana do Rejestru Przedsiebiorców Krajowego Rejestru Sadowego pod numerem: 0000021828, dla której dokumentacje przechowuje Sad Rejonowy Gdansk - Pólnoc w Gdansku, VIII Wydzial Gospodarczy Krajowego Rejestru Sadowego, o kapitale zakladowym i wplaconym w wysokosci: 277.493.500,00 zlotych, NIP: 586-000-78-20, REGON: 190024711-- //www.freelists.org/webpage/oracle-l