Hot answers tagged oracle-rac
No, nothing in SQL Server can give you the same thing out of the box. Currently, the only SQL Server technology that allows simultaneous writes at multiple nodes is Peer-to-Peer replication. Note that I did not to say "write scale-out," because it works in a way such that the entire system has the write capacity of only a single node. The introductory ...
The straight answer to your question is no, SQL Server does not have equivalent functionality. There are aspects of SQL Server that give you the kind of failure tolerance that you want (even as far back as SQL Server 2005 when using DB mirroring and a mirror-aware application), but there is not a 1:1 with Oracle RAC.
I'm a DBA supporting both SQL 2000-2012, Oracle 11g, and Oracle 11g RAC. IMO, Always On Availability Groups in SQL 2012 comes very close to the availability and scalability of RAC at much less cost in both dollars and complexity. You can scale out reads by querying against the mirrors, but you'd want to direct all DML to the primary server (SQL Server ...
I can see why Oracle RAC can handle split brain and PXC cannot. What separates them in their architecture and data storage. In what ways ??? Oracle RAC All RAC Instances deal with only one set of database files Each RAC Instance has its own Log Buffer and LGWR (Log Writer) process Writes to any Oracle RAC instance, even on nodes that go down temporarily, ...
Although I haven't tried it, I would tend to suspect that you'll run into problems when your UNDO_RETENTION exceeds the length of time that Oracle maintains its SCN to timestamp mapping. If memory serves, that is roughly 1 week (well, if memory serves, it was 1 week in the 10g days and I'm not aware of anything that would have changed that in 11.2). I ...
Very high is a relative term that depends on perspective. You could mean 1 hour, 1 month, 1 year, etc. Assuming you mean something between one minute and one month, the answer will depend on how much undo is being produced and how much storage you have available. I haven't seen anything higher than two weeks. Oracle automatically manages the undo space ...
I got following results SELECT SYS_CONTEXT('USERENV','SID') FROM DUAL; -- 5276 SELECT * FROM gv$session where SID = SYS_CONTEXT('USERENV','SID'); -- No result SELECT * FROM gv$session where SID =5276; -- 4 results for 4 node RAC -- 1 result matches my USERNAME,OSUSER, MACHINE and PROGRAM -- 3 results are different from my USERNAME,OSUSER, MACHINE and ...
My Oracle Support has a certify tab which lists current certifications, including the one you are looking for. Here is how: Select "Oracle Database" as the Product. Select the release "188.8.131.52". Click the link "Check certifications with another product. Select the "Product Category" radio button. In the Category drop down select "Operating Systems".
dbms_scheduler.set_attribute is what you're looking for - it forces a job to run on a given node (specified by instance_id): begin dbms_scheduler.create_job ( job_name=>'PHIL', job_type=>'plsql_block', job_action=>'NULL;', repeat_interval=>'freq=minutely;interval=2'); end; / begin dbms_scheduler.set_attribute('PHIL','instance_id',1); end; / ...
There aren't any special considerations that need to be taken into account when setting up a RAC->No RAC Primary->Standby configuration. In fact, there's a White Paper written by Oracle which explains the setup. The Oracle documentation is here.
A better comparison of AlwaysOn would be Oracle's Data Guard feature. Active-Passive clustering. (yes, you can read from standby, but it is read only, so still only one node is active") Oracle RAC is a completely different animal, and active-active clustering. I did not see any moves if Microsoft will ever want to implement that.
Oracle support has been no help. After about a week of the jobs sometimes running they stopped running completely. Every single job got an initialization error every time it ran and every time it was retried. We are in the process of re-creating the repository and migrating to dbms_scheduler jobs.
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