October 8, 2010 at 4:12 am
Jeff Moden (10/8/2010)
Why wouldn't "Federated Servers" in SQL Server do the same thing?
That's when you split a database across multiple servers so that each holds a piece.
RAC has multiple instances reading and writing the same database.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability
October 8, 2010 at 5:55 am
saurabh.deshpande (10/8/2010)
So, what they are giving new with Oracle 10g/11g.So, what's new?
Now it works 😉
_____________________________________
Pablo (Paul) Berzukov
Author of Understanding Database Administration available at Amazon and other bookstores.
Disclaimer: Advice is provided to the best of my knowledge but no implicit or explicit warranties are provided. Since the advisor explicitly encourages testing any and all suggestions on a test non-production environment advisor should not held liable or responsible for any actions taken based on the given advice.October 8, 2010 at 6:05 am
PaulB-TheOneAndOnly (10/8/2010)
saurabh.deshpande (10/8/2010)
So, what they are giving new with Oracle 10g/11g.So, what's new?
Now it works 😉
Really, does it? 😛
-- Gianluca Sartori
October 8, 2010 at 6:39 am
GilaMonster (10/8/2010)
Jeff Moden (10/8/2010)
Why wouldn't "Federated Servers" in SQL Server do the same thing?That's when you split a database across multiple servers so that each holds a piece.
RAC has multiple instances reading and writing the same database.
Ah... no partitioning then on the Oracle RAC side which is quite different than the horizontal partitioning you have to do with Federated Servers.
--Jeff Moden
Change is inevitable... Change for the better is not.
October 8, 2010 at 6:46 am
Jeff Moden (10/8/2010)
GilaMonster (10/8/2010)
Jeff Moden (10/8/2010)
Why wouldn't "Federated Servers" in SQL Server do the same thing?That's when you split a database across multiple servers so that each holds a piece.
RAC has multiple instances reading and writing the same database.
Ah... no partitioning then on the Oracle RAC side which is quite different than the horizontal partitioning you have to do with Federated Servers.
Exactly, you got it.
In practical terms that means...
1- Oracle RAC is able to load balance between nodes while Federated Servers don't.
2- If a node of Oracle RAC goes down other nodes still provide access to the whole database while Federated Servers don't.
3- Oracle RAC allows for zero downtime maintenance windows down to the hardware level while Federated Servers don't.
_____________________________________
Pablo (Paul) Berzukov
Author of Understanding Database Administration available at Amazon and other bookstores.
Disclaimer: Advice is provided to the best of my knowledge but no implicit or explicit warranties are provided. Since the advisor explicitly encourages testing any and all suggestions on a test non-production environment advisor should not held liable or responsible for any actions taken based on the given advice.October 8, 2010 at 6:47 am
Gianluca Sartori (10/8/2010)
PaulB-TheOneAndOnly (10/8/2010)
saurabh.deshpande (10/8/2010)
So, what they are giving new with Oracle 10g/11g.So, what's new?
Now it works 😉
Really, does it? 😛
It does indeed - surprised? 😀
_____________________________________
Pablo (Paul) Berzukov
Author of Understanding Database Administration available at Amazon and other bookstores.
Disclaimer: Advice is provided to the best of my knowledge but no implicit or explicit warranties are provided. Since the advisor explicitly encourages testing any and all suggestions on a test non-production environment advisor should not held liable or responsible for any actions taken based on the given advice.October 8, 2010 at 6:52 am
There are 3rd party tools that will do the job for SQL Server, things like GRIDScale, although they have been bought out. Basically you can scale the reads, but not the writes.
REMOVED as promised... old posts... I dont support anything on Oracle, so my mistake.
October 8, 2010 at 7:01 am
grahamc (10/8/2010)
From my understand (mostly reading of forums, blogs and web articles) the Oracle RAC is mostly a marketing gimmick, nice to helps sell the product, but not really applicable in the real world. Most said that it was very very expensive and damn near impossible to get running properly. I may well be wrong on this and if I am will gladly apologise and remove this post.
This is indeed a very unfortunate post.
Oracle RAC is a solid platform. I personally support several mission critical databases based in this technology. Don't know who are "most" but "they" got it wrong.
_____________________________________
Pablo (Paul) Berzukov
Author of Understanding Database Administration available at Amazon and other bookstores.
Disclaimer: Advice is provided to the best of my knowledge but no implicit or explicit warranties are provided. Since the advisor explicitly encourages testing any and all suggestions on a test non-production environment advisor should not held liable or responsible for any actions taken based on the given advice.October 8, 2010 at 7:17 am
October 8, 2010 at 7:31 am
grahamc (10/8/2010)
PaulB-TheOneAndOnlysince you have it running... does that mean if you have a RAC environment running, that if you are hitting performance problems that a shiny new server can be added to improve the performance?
It all depends of what you mean by "performance problems". Performance problems may be originated by I/O bottleneck at the Storage subsystem level, improper database design, poor indexing strategy, poor performing code, etc., etc. Each one of those "performance problems" require a different solving strategy that may not involve to add processing power.
Answering your particular question the answer is: Yes.
You can add a node to the RAC anytime you want. This is transparent for the user community meaning you do not have to shutdown database to do it.
RAC will recognize the new node and will start routing traffic to it - literally "in a split-second".
_____________________________________
Pablo (Paul) Berzukov
Author of Understanding Database Administration available at Amazon and other bookstores.
Disclaimer: Advice is provided to the best of my knowledge but no implicit or explicit warranties are provided. Since the advisor explicitly encourages testing any and all suggestions on a test non-production environment advisor should not held liable or responsible for any actions taken based on the given advice.October 8, 2010 at 7:42 am
PaulB-TheOneAndOnly (10/8/2010)
grahamc (10/8/2010)
PaulB-TheOneAndOnlysince you have it running... does that mean if you have a RAC environment running, that if you are hitting performance problems that a shiny new server can be added to improve the performance?
It all depends of what you mean by "performance problems". Performance problems may be originated by I/O bottleneck at the Storage subsystem level, improper database design, poor indexing strategy, poor performing code, etc., etc. Each one of those "performance problems" require a different solving strategy that may not involve to add processing power.
Answering your particular question the answer is: Yes.
You can add a node to the RAC anytime you want. This is transparent for the user community meaning you do not have to shutdown database to do it.
RAC will recognize the new node and will start routing traffic to it - literally "in a split-second".
Obviously the IO is limited by the system it resides on, which would not be part of the RAC solution, different discussion altogether.
So if its a memory, CPU issue, it will scale.... Cool!!! Thank you :smooooth: makes a little more sense now
October 8, 2010 at 11:47 am
grahamc (10/8/2010)
So if its a memory, CPU issue, it will scale.... Cool!!! Thank you :smooooth: makes a little more sense now
No. Not as simple as that I'm afraid. It depends very much on your workload as to whether it will scale in anything like a linear way. The overhead for the cache fusion can be quite high.
October 8, 2010 at 12:21 pm
grahamc (10/8/2010)
So if its a memory, CPU issue, it will scale.... Cool!!! Thank you makes a little more sense now
The focus of Oracle RAC is high availability 🙂
You can always add CPUs and Memory whitout the need of adding a new node.
_____________________________________
Pablo (Paul) Berzukov
Author of Understanding Database Administration available at Amazon and other bookstores.
Disclaimer: Advice is provided to the best of my knowledge but no implicit or explicit warranties are provided. Since the advisor explicitly encourages testing any and all suggestions on a test non-production environment advisor should not held liable or responsible for any actions taken based on the given advice.October 8, 2010 at 1:08 pm
DEC Rdb was introduced with clustering similar to RAC in 1984. My assumption is that Oracle acquired a lot of the technology for RAC when they bought Rdb from DEC in the 1990’s. DEC Rdb was a bit different because the shared storage and distributed locking was built into the VMS operating system so that Rdb could just use things available at the OS level.
Oracle Rdb on VMS is still available and in use. I believe it supports clusters with 90+ nodes, and is sometimes used for “disaster tolerant” clusters with cluster nodes at multiple sites so that the application can stay active even if a datacenter is lost.
October 8, 2010 at 3:15 pm
Michael Valentine Jones (10/8/2010)
DEC Rdb was introduced with clustering similar to RAC in 1984. My assumption is that Oracle acquired a lot of the technology for RAC when they bought Rdb from DEC in the 1990’s. DEC Rdb was a bit different because the shared storage and distributed locking was built into the VMS operating system so that Rdb could just use things available at the OS level.Oracle Rdb on VMS is still available and in use. I believe it supports clusters with 90+ nodes, and is sometimes used for “disaster tolerant” clusters with cluster nodes at multiple sites so that the application can stay active even if a datacenter is lost.
Nicely done Michael.
Interesting you bring this to the table.
I understand that key Oracle RDBMS features we see today like Cost-Based Optimizer, Partitioning and Bitmap indexes are actually Oracle Rdb technologies migrated to the RDBMS side.
_____________________________________
Pablo (Paul) Berzukov
Author of Understanding Database Administration available at Amazon and other bookstores.
Disclaimer: Advice is provided to the best of my knowledge but no implicit or explicit warranties are provided. Since the advisor explicitly encourages testing any and all suggestions on a test non-production environment advisor should not held liable or responsible for any actions taken based on the given advice.Viewing 15 posts - 16 through 30 (of 31 total)
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