differences

[sripalli]

hi guys
can u plz tell me the exact difference between parlell server, distributed database system & stand-by servier

thanks in advance

sri

[Zamial]

I can't exactly but I can tell you that Parallel server means you have one database.

And there is more than one instance reading that database.

there fore there is 2 SGA's etc..... One in each instance.

You could in fact have 5 instances on 5 different machines.

So if one instance is busy accessing the database and its SGA is full - You can use a different instance to run your queries and there is a totally different SGA on that machine so you can in theory make more use of your database.

I havent really come across the other two.

[Zamial]

I think a distributed database system is one where you have more than one database on the same network.

A standby database is one that can be used to replace an existing database should it fail.

So every night you populate the standby with todays data. Then if your database crashes you have a standby server waiting to take over.

[santoshym]

Hi

Parallel sever : Is a database stored in a centralized storage section like on a net filer or a emc.Parallel server is one single database and multiple instance running on differnt systems accessing the common storage that is the database.so the advantage over here even one if one of the instance fails on one of the machines there are the other instances which will be running so the client can connect thru the rest of the instance.This technology is usefull for high availability of data.

Distributed system : where the systems are distributed on a WAM or VPN. whenever you access your data if the data is not available in ur local server it automatically gets connected to a remote server retreives your data and passes it back to the client.

Stand by server : Database cloned on to a differnt server for fail over.

Regards