Hot answers tagged

8

Virtualizing an Oracle RAC isn't necessarily a stupid idea, but it should only be done with a full understanding of the benefits and risks. You are asking questions, so that is a good step in the right direction. Your question doesn't say which virtualization technology, the Oracle version, or the edition. For now I will assume this is for production on ...


8

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 ...


6

SCAN is supposed to give you connect-time failover, but not run-time failover (like TAF). Where did you get the (mis-)information that SCAN also means TAF?


5

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.


5

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 ...


4

Two transactions won't share an SCN barring a bug in Oracle. Exactly how Oracle ensures this varies by version, platform, and configuration settings. For example, back in the Oracle 9.2 days, there was by default a non-zero max_commit_propagation_delay which meant that a row that was inserted on one node and committed might not be immediately visible to a ...


3

As it turns out, the ODA is factory configured with active-backup bonds. I've tested this to work well without any switch-side LACP/EtherChannel configuration, and each bonded connection may be split across two switches. In my tests, no simulated failure or network reconfiguration caused more than a a few hundred milliseconds worth of network outage. This ...


3

We just did the same thing. install software in new machines and configure different cluster copy tnsnames.ora, orapwSID files to new machines and prepare pfile you may need to add SID to /etc/oratab file on new machines shutdown database on old machines dismount ASM diskgroups on old machines present LUNs to new machines mount diskgroups on new machines ...


3

The recommendation is to have log switches occur a few times an hour. If you have a 100 log switches an hour with 50MB redo logs, you need e.g 1GB redo logs for 5 log switches/hour. 100*50 MB redo/hour for a 6.5GB database is unusually much though. You can add the new logs, e.g: ALTER DATABASE ADD LOGFILE THREAD 1 SIZE 1G; ALTER DATABASE ADD LOGFILE THREAD ...


3

Yes, it is possible. https://docs.oracle.com/database/121/NTDBI/intro.htm#NTDBI2648 Oracle Database supports multiple Oracle homes. You can install this release or previous releases of the software more than once on the same system, in different Oracle home directories. This allows flexibility in deployment and maintenance of the database ...


2

Changing the order of the SET seemed to make a difference, as it is working now. create or replace TRIGGER schema.django_nls_tr AFTER logon ON DATABASE BEGIN execute immediate 'ALTER SESSION SET NLS_TERRITORY = ''AMERICA'' NLS_DATE_FORMAT = ''YYYY-MM-DD HH24:MI:SS'' NLS_TIMESTAMP_FORMAT = ''YYYY-MM-DD HH24:MI:SS.FF'''; END; I don't really like this ...


2

DISCLAIMER : Not an Oracle DBA Use srvctl, the grid control program that allows you to manipulate parts of the RAC Cluster Usage: srvctl <command> <object> [<options>] commands: enable|disable|start|stop|relocate|status|add|remove|modify|getenv|setenv|unsetenv|config objects: ...


2

We solved this at my previous company by scheduling a cron job for out of trading hours to grow the tablespace when it fell to within a couple of standard deviations of average daily growth free. I researched it extensively at the time, and there is no way to tune the threshold for when Oracle does it (and you probably wouldn't want to anyway, since you ...


2

30min for 1TB is quite normal. That all writing stops is also normal if your tablespace completely run out of space. When writes has nowhere to go they have to wait for the RESIZE operation to complete. If one extends datafile while there is still space in it database I/O does not stop. Just why you extended for such huge amount? Now those +1TB will add to ...


2

I found the solution. --------------------------------------To shutdown ----------shutdown database instance first $. oraenv >mydb1 >/u01/app/oracle/product/11.2.0/db_1 $sqlplus / as sysdba SQL> shutdown immediate; ---------stopping Oracle Clusterware, It will shutdown ASM instance itself $ su - # cd /u01/app/11.2.0/grid/bin/ # ./crsctl stop ...


2

They are Oracle Resource Manager waits. Resource Manager is a set of Oracle functionality that lets you prioritise work. See the list of possible waits in the documentation.


2

Yes, Oracle RAC is built using multiple servers sharing their memory - Cache Fusion - and they all access the same shared storage where the database resides. In Oracle an Instance is just the collection of processes that acts as an interface between client connections and the actual database. Since all storage is shared, when a server crashes, a surviving ...


2

You can check the value of the CLUSTER_DATABASE parameter: SQL> select name, value from v$parameter where name = 'cluster_database'; NAME VALUE --------------------- --------------------- cluster_database TRUE According to the Oracle Database Reference: CLUSTER_DATABASE is an Oracle RAC parameter that specifies whether or ...


2

i've found the definitive answer from the oracle docs http://docs.oracle.com/cd/E11882_01/license.112/e47877/editions.htm#DBLIC109 in the Oracle Database Standard Edition and Oracle Real Application Clusters (Oracle RAC) section, it specifies "Oracle Automatic Storage Management is required for creating and managing all Oracle database file types. Raw ...


2

What is node eviction? Word Meaning(Merriam Webster Disctionary): to force(someone) to leave the place. The process of removing the failed(due to various reasons) node from the cluster is known as eviction. Prior to 11gR2 Oracle tries to prevent from split brain situation by quickly rebooting the failed node . After 11gr2 Clusterware will attempt to ...


2

Let me start with another question. Is catproc.sql/catalog.sql really required? Try creating a new database manually: create database; And stop here, don't run any scripts. You have a "functioning" database, you can create tablespaces, users, query v$ views, create tables, indexes, insert and query data. You can even create user-managed backups. Now try ...


1

When you drop user on primary then this will be also reflected on secondary site. Also impdp will work as expected. But when you are about to import large amount of data MAA might slow down the whole procedure significantly. If you have enough experience with RMAN you might try: shutdown and disconnect the secondary import data into master backup master ...


1

I tried the above suggestions, but did not work, such as select SQL did not get results and I still cannot drop the undo table space. The fundamental issue is that the old undo table space is still registered in Oracle as its undo, therefore we need to change it to the new undo table space. Here are what I did and it worked: create a new UNDO table ...


1

You don't want to start dropping connections. How do you know what those connections are doing, and what might break if those connections are dropped. You are better off waiting for sessions to start using the new tablespace. Eventually, the old undo tablespace will be not longer be in use. At that time you can drop it. If you need disk space you can try ...


1

the error message mean the tablespace is in use, and since the undo tablespace is critical tablespace you need to shut it down first by using: SELECT a.name,b.status , d.username , d.sid , d.serial# FROM v$rollname a,v$rollstat b, v$transaction c , v$session d WHERE a.usn = b.usn AND a.usn = c.xidusn AND c.ses_addr = d.saddr AND a.name IN ( ...


1

It looks like resource manager is in action. Your dba configured this most likely to give certain processes priority over other processes. Oracle Scheduler is fuly integrated with Resource Manager but the way this is presented is a bit misleading. Often it has nothing to do with Scheduled Jobs at all. You can find which sessions are waiting for resource ...


1

First of all, I checked that there were no extents on DISK1. $ . oraenv ORACLE_SID = [+ASM1] ? SQL> select PXN_KFFXP, -- physical extent number XNUM_KFFXP, -- virtual extent number DISK_KFFXP, -- disk number AU_KFFXP -- allocation unit number from X$KFFXP where DISK_KFFXP=1; no rows selected I cleared the ...


1

This is a bug which is fixed in 11.2.0.3. Have a look at bug# 9897335. If you have a support contract, you can request a backport if it is feasible. In addition the error tell you which client it is waiting on. Further information can be retrieved from v$asm_client.


1

Investigate v$session view about what particular event is causing those cluster waits. E.g.: select s.event, s.* from v$session s order by s.event; event column will get you offending event event name. Then you can google the event or add information to you question. Also "Blocking Sessions" screen in Performance menu in Enterprise Manager in such cases ...


1

Try using these 3 options : oracle.install.option=INSTALL_DB_SWONLY \ oracle.install.db.InstallEdition=EE \ oracle.install.db.isCustomInstall=true



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