Is there anyway to take a half-step towards RAC or GRID by getting some components like shared disk now? The only way I can see using shared disk is
OPS - replaced by Dataguard
RAC - Too expensive for us right now
3rd party - ?
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Is there anyway to take a half-step towards RAC or GRID by getting some components like shared disk now? The only way I can see using shared disk is
OPS - replaced by Dataguard
RAC - Too expensive for us right now
3rd party - ?
Not really sure what you are trying to do.
Sure you can share disk between hosts.
You can also use shared disk to setup failover at the OS level by setting up cluster Eg: Veritas Cluster.(Oracle will be installed on the shared disk and can be accessed from a single node. Incase the node goes down then failover happens and Database will be accessed from a second node)
I thought that if two oracle instances were going to hit the same datafiles ( rather than dividing the disk space ) you had to have parallel server or rac or grid to sort out the conflicts.Quote:
Originally posted by marist89
Not really sure what you are trying to do.
Sure you can share disk between hosts.
Sorry if I am not making much sense here, I rotated off Oracle for sql server firefighting the last 3 months. Oracle is stable but they want me to move it to new platform and if I do that I want to build something interesting.
I have already proven that a read-only ( except for new partition loads ) data warehouse needs nothing special to have 2 instances read the same datafiles, you just use transportable tablespaces to inform the instance that did not perform the data load.
But this time its OLTP. Wondering if I have any options to share datafiles and not just the disk system in a read-write OLTP system.
THANKS
Two instances same set of datafiles without RAC, no way.
I thought so. But it does work for DW if you just need read-only tablespace, but then your sort of forced to make each new partition live in its own tablespace so its awkward for frequent updates which its seems like everyone now wants their DW updated realtime.Quote:
Originally posted by marist89
Two instances same set of datafiles without RAC, no way.
Thanks rad_jen, I forgot about veritas, if its a lot cheaper than RAC then we could get underway with the shared disk and still have failover capacity.
Yes, its lot cheaper than RAC.
Hardware failover + Dataguard is the popular solution for the sites that can't afford RAC.
Will you please show me some docs (in the net) explaing this functionality. ie two or more instances in a OS clustered environment working on the same database without OPS or RAC. Very much interesting. :confused:Quote:
Originally posted by BJE_DBA
I thought so. But it does work for DW if you just need read-only tablespace,
Thomasps,
When I ran a terabyte Datawarehouse for qwest and one for AT&T I presented the 'poor mans' approach to management but recommended RAC.
'Poor mans' allowed no updates. We loaded our DW monthly so 24 partions on all the tables for a 2 year window was nothing. We were going to daily processing so I looked into it and was comfortable with 712 partitions/tablespaces based on the type of queries we typically ran against it. The load automation would go like this, add a new partition in a new tablespace, bulk load it, index it, exchange it including indexes for all such fact and dim tables. Analyze it.
Set tablespace to read-only
Export the DD info as Transportable Tablespace, Import it into the 2nd machine.
Query away....
Boy, you know what is RAC or OPS?!?! That is not even close, you are not reading same datafiles, you are reading each database own datafiles!Quote:
Originally posted by BJE_DBA
Set tablespace to read-only
Export the DD info as Transportable Tablespace, Import it into the 2nd machine.
Query away....
What you do is not even close, what you do is what we used to do since 2000 for DWH ETL processes.
What are you talking about? There was one set of files - PERIOD. Transportable tablespaces contains DD info, however I never transported the files themselves just the dd info left them where they are, let it point to the original file locations.Quote:
Originally posted by pando
Boy, you know what is RAC or OPS?!?! That is not even close, you are not reading same datafiles, you are reading each database own datafiles!
What you do is not even close, what you do is what we used to do since 2000 for DWH ETL processes.
No duplication of data - PERIOD.
Jeez what a nutjob, Oracle even agreed it would work, were you there? Have you tried it and proven me wrong ?
Woops... This is very interesting. Very much new for me!
Well, what is your OS and oracle Version?
Any docs around you to share with us? Even in metalink?
Very much appreciated
I recommended RAC but the CEO also wanted a cheap option. I was suggesting that it could be done by having 2 instances pointing to the same datafiles if they dont need to write to them. Read-only. The network guy insisted it would not work without the expensive shared disk cabinet and special Oracle software ( RAC or OPS ). I talked to Oracle about getting instance #2 to see the same datafiles by importing their tablespace DD info via Transportable Tablespaces and they said it should work. We were on Sun and Windows, to quickly illustrate my point without the shared disk cabinet I setup 2 instances on one Windows machine and loaded the DD info into instance #2 for the SAME un-moved un-copied read-only tablespace datafiles.Quote:
Originally posted by Thomasps
Woops... This is very interesting. Very much new for me!
Well, what is your OS and oracle Version?
Any docs around you to share with us? Even in metalink?
Very much appreciated
One set of datafiles, 2 instances READ-ONLY. Both instances up and both querying the tablespace fine.
I recommended RAC because its would be supported by Oracle and because they quite often asked me to go back to the already loaded months of data and change certain values across the board. In the cheap method that would be awkward. Again this was just to demonstrate that it could be done, I never took it any further but found it interesting.
Eventually they could not afford RAC and started talking about not paying Oracle for the Partitioning I had been using so I quit and took a contract elsewhere.
ok I make a pardon but since in your previous posts you didnt say you only imported the metadata I thought you was moving the datafiles as well
Oracle says it should work but do they support this configuration if there are corruptions?
I doubt they would offer much help. What I really wanted was RAC experience, but the CEO wanted to know why it was so expensive, wanted to see me come up with some alternative.Quote:
Originally posted by pando
ok I make a pardon but since in your previous posts you didnt say you only imported the metadata I thought you was moving the datafiles as well
Oracle says it should work but do they support this configuration if there are corruptions?
When I brought the Oracle sales/consultants in to discuss RAC they told us we had been using partitioning without paying for it ( I did not know this ), that only aggravated the situation. No way could they afford RAC.
Is there a way for me to build a simple RAC in my basement lab with all my computers? Is there any shared disk that is 'inexpensive' at the low end that is suitable for this ? I am not even sure if I can get my hands on the correct Oracle software without 'purchasing' the RAC option. thx.