OPS in 8i vs RAC in 9i !!!!!

[Henrique Silva_3]

Does anyone out there has any information on this subject ?

I have attended a replication class a couple week ago at oracle, and we were told that replication works better under 9i, for it can deal with subsets of data better. I also heard, but did not go much further, that RAC is better then OPS, but did not get any details on WHY !!!!

Has anyone here worked with both and give us a brief summary, and maybe point me out where I can find more info ? Metalink papers are so outdated, it is not a good place to look !!!

Thanks,

Henrique Silva

[Tom Geudens]

Hi,
I'm afraid I can't give you a lot of information, since I'm only up-to-speed with Replication/OPS in 8i, but unless there's been a major change, you should note that replication is NOT THE SAME.
Example :
Consider a retail cluster with two servers for hardware redundancy. Since this is retail it's important that the same data is only changed once. OPS does this automatically, since only 1 database is shared between both servers. It might be possible with Replication, but it would require you to program the "keeping the 2 databases concurrent".

Unless there has been a major change in 9i Replication off course ;-)

Regards,
Tom

[Henrique Silva_3]

Sorry Tom, my question was a bit confusing.

I understand what replication and OPS are. My point here was that since replication, supposedly works better on 9i, then, RAC ( 9is term for OPS ) is also better.

I am looking for reasons such as what the differences are between OPS and RAC, so that I can try to implement either one. And why should I implement RAC as opposed to OPS !!!

I hope this clarifies things a bit !!!

Cheers,

Henrique Silva

[cart]

Hi,

From what I have understood, the main difference between Rac and OPS is about the cache fusion.
The problem with parrallel database is when both node want to modifie the same block. With OPS, the block is modified by the first node, then it is written on the disk and then the 2nd node reads it from the disk to be able to modifed it. With Rac, the block can be transfered by the high speed cluster inter-connect (which is much faster (20-40) than the disk).
So you should get real improvement for OLTP database.

Also I think Compaq TrueCluster (V5) is the best environement for 9iRac because of the cluster filesystem. You can have the database set up with filesystem, and forget the raw divice.

HTH,

Sundanc

[cart]

You can also check this link
http://otn.oracle.com/products/oracle9i/htdocs/9iRAChp.html

S

[Ron Gordon]

I have OPS 8.1.7 running on my system. And although it is solid, Oracle is desupporting 8i within the next few year. It appears you are going to a clustered system. If so 9i whould be the way I would go.