After working at A.T.U Auto-Teile-Unger headquarters for over six years, there’s a new challenge calling on January 1st, 2009, and hopefully, it’s for a long time again. I guess it’s a good time to look back: […]
Category: Oracle
What’s the difference between Larry Ellison and god?
Oracle: Remove scheduler jobs in a loop
If there are too much scheduler jobs in an Oracle database, the CJQ process may die unexpectedly. This has nothing to do with job history, not, it’s the number of jobs known to the system. In my experience, the critical number is somewhere around 32.000 in 10.2 64bit. By the way, that’s the solution for […]
Oracle: How to stop a (MTS) dispatcher process – mad behaviour of ALTER SYSTEM
Manually stopping a dispatcher process is one of the things I have to look up each time, since it’s needed not that often. And, the word “dispatcher” does not appear in the command line! 🙂 alter system shutdown immediate ‘D000’; where “D000” is the dispatcher process name selected from v$dispatchers or gv$dispatchers. (In the latter […]
Oracle 10g Data warehouse ORION benchmark, size 20TB, 1200MB per second
During the last days, I have had the opportunity to test and benchmark a data warehousing hardware, that’s really fast for its money. It’s not suitable for real/available production, since it depends on disk striping over a bunch of components, but I considered it as a good way to push the limits a bit. Result: […]
Attended “Reactive Performance Management” with Craig Shallahamer
Monday and today (Tuesday) I attended a 2-days Oracle University class with Craig Shallahamer from OraPub, taking place in Munich. Honestly, I have had no expectations at all, so there has been nothing to be crestfallen or to be fulfilled. I just was looking forward to the one or other hint how to find the […]
memlock config for Debian Lenny
Hi, today I tried to start Oracle XE with parameters “pre_paged_sga=true” and “lock_sga=true” on my Debian Lenny toybox. But Lenny has had a rather strict and really sticky value for the user’s maximum amount of pinned memory (ulimit -l) value: 32 (kb). First attempt, change /etc/security/limits.conf: oracle – memlock 1073741824 Result: Nothing, “ulimit -l” as […]
Oracle DML Parallel Execution Don’ts
Have you ever waited on a parallelized statement? Parallel execution is said to be fast, efficient, system-exhausting. Far from that! There’s a 10.2.0.4 x86_64 system with 16 cores and over 600MB/s write-IO ability, one statement running, one CPU burning, one developer waiting. For days. Finally, at the end of the week, the admin is involved. […]
Nerd compliments.
If anybody ever considers joining irc.freenode.net #oracle (what I’d recommend for all Oracle interested folks), be prepared for being treated like that: <nayyares> it worked !!! <usn> wait some time, it might crash, or restart all cluster services to see if there is a boot bug <nayyares> ok, i am monitoring usn <Rudemeister> Im also […]
TEMP tablespace too small
Today I got a mail from my grid control: “Tablespace TEMP1 is 97% full”, acting for one of the single instance servers. No problem, you may think, this might happen. It’s an OLAP database, so I wasn’t afraid of big numbers as well. But as you can see, using all this huge temp tablespace for […]
Cleanly removing an agent or host target from Oracle Grid Control 10.2.0.4
Removing a host/agent in Oracle’s Grid Control can be unnerving: There are enough dependencies between the agent, the (cluster-)database, the listener, the host and so to make your deleting action an endless sequence if you are following them. But GC really becomes stubborn if the agent we are about to remove is unavailable: due to […]
Grid Control startup fails, installUser=%s_userName%
Oracle seems to have an uncommon sense of humor. Executing gcstartup after patching the grid control server to 10.2.0.4 (Linux x86) fails with: /bin/su: user %s_userName% does not exist I am not surprised, since this is windows’ environment variable notation, and unknown to my Linux shells. Solution: In the head of /opt/oracle/grid/oms10g/install/unix/scripts/omsstup replace installUser=%s_userName% with the username […]
Oracle DB: Automatic tracing for all sessions of a user
Hi, SQL tracing is nice to find out details about several issues. But there is no out-of-the-box solution to enable tracing for a user, only for session- or system-wide tracing. But there’s a trick to close this gap. It’s old, but stil useful: Use a logon trigger to enable tracing for all sessions of a […]
Oracle expdp utility i18n – strange
Export> kill_job Möchten Sie diesen Job wirklich stoppen ([yes]/no): yes Möchten Sie diesen Job wirklich stoppen ([yes]/no): yes Möchten Sie diesen Job wirklich stoppen ([yes]/no): yes Möchten Sie diesen Job wirklich stoppen ([yes]/no): yes Möchten Sie diesen Job wirklich stoppen ([yes]/no): yes Möchten Sie diesen Job wirklich stoppen ([yes]/no): YES Möchten Sie diesen Job wirklich […]
Effectice load balancing for a (web?) service in RAC 10gR2
Hi, had to review service creation with DBMS_SERVICE package for a good-feeling load balancing in Oracle RAC 10gR2 several times – now I have to write it down for myself. 🙂 I needed it for a web service using shared server today, but the generic syntax is useful for all other purposes as well. Basic […]
ORA-00600 [kgeade_is_0]
Have a look at this nice one (alert log), seen in 10gR2 (10.2.0.4 64bit on Linux): ORA-00600: Interner Fehlercode, Argumente: [kgeade_is_0], [], [], [], [], [], [], [] And from the trace file: Current SQL statement for this session: select tablespace_id, rfno, allocated_space, file_size, file_maxsize, changescn_base, changescn_wrap, flag from GV$FILESPACE_USAGE where inst_id != :inst and […]
Disabling (or enabling) general job execution in Oracle 10g
Hi, disabling and enabling job execution in Oracle DB has two ways: If you are using dbms_jobs, it’s handy to set job_queue_processes to zero to disable the execution of jobs, and set it to a value >0 (maybe 100) to enable. If you are using dbms_scheduler, this parameter does not work for you. You will […]
Find out your character set in Oracle DB
Hi, since ‘show parameter’ does not tell you your database charset, use this statement to see how your characters are stored: select * from nls_database_parameters where parameter=’NLS_CHARACTERSET’; Regards Usn […]
Oracle Database with SGA of or larger than 16GB
Hi, using large SGA’s requires 64bit Oracle RDBMS, of course. But furthermore, some OS settings are to be done. SUSE walks it’s own lane, quite as usual, so I will provide two ways for doing without ORA-27102. […]
Another lecture “Basics of database technology” in German
Tomorrow at 10 a.m. I’ll give a lecture about the “Basics of database technology” in German language for 9th-formers of Augustinus Grammar School in Weiden. See the handout and the presentation here. Regards Usn […]
Oracle 10gR2 Clusterware on Novell/SuSE SLES10 on multipath devices
Hi RAC-DBAs, installing the Oracle Clusterware CRS 10.2 on SLES10 with its multipath devices can be tricky. Background: The tool formatting the OCR disks, clsfmt.bin, is buggy concerning multipath / device mapper devices and you will see root.sh fail and clsfmt spit out errors like: clsfmt: Failure trying to resize OCR file from … bytes […]
Lecture “Highly available Communications Server” (Oracle Database) at DOAG conference 2007
Hi, I’ll give a lecture about high availability with Oracle RAC and Dataguard at DOAG Conference 2007 (annual conference of the German Oracle User’s Group). The talk will be in German. (“Ein hochverfĂĽgbarer Kommunikationsserver mit RAC, ASM, redundant shared media und DataGuard”) When? Thursday, November 22nd 2007 1300hrs Where? CCN CongressCenter NĂĽrnberg Ost Messezentrum D-90471 […]
Scheduler hangs in Oracle Database 10g
Hi, sometimes the 10g scheduler refuses to start jobs any more. I do not know why at the moment, but as a workaround you can just kill -9 the “coordinator job queue (CJQ0)” process from OS level. The process will be named like “ora_cjq0_SID” in a RAC. PMON does a restart of the coordinator after […]
How to fail over a client transparently in a dataguard switchover/failover scenario
Hi, with using dataguard (Oracle’s hot/cold standby database solution) you have the challenge to make a failover or a roleswitch between the primary and the standby database transparent to the clients. If you don’t, you will have a (partially) loss of service: Clients tnsnames.ora’s will need reconfiguration or the application has to use another TNS […]
Lecture “Basics of database technology” in German
Hi, today I’ll give a lecture about the “Basics of database technology” in German language for our Linux User Group Mitterteich (http://lug-mitterteich.de.vu) See the Handout and the Block handling overview. Regards Usn […]
Lost, deleted or corrupted a voting disk (quorum) in Oracle RAC 10.2 ?
Hi Folx, whenever you lost, deleted or corrupted a quorum aka voting disk in Oracle Real Application Cluster (RAC) 10.2, you have three options: 1) Reinstall your Clusterware, see Metalink Note 279793.1 2) Replay a backup taken with “dd if=/dev/votingdisk of=/backup/votingfile bs=4k” 3) Have a look at Metalink Note 399482.1 and the RAC Administration and […]
How to move or add a controlfile when ASM is involved
Hi folx, sometimes, you may want to add or move a controlfile. On OS file system, this is no problem. Just “shutdown immediate”, change the CONTROL_FILES init parameter, copy or move the controlfile, and startup again. With ASM involved this is not possible, since the ASM does not allow direct move or copy commands. You […]
Grid Control Agent install without Metalink Access
Hi folx, if you ever need to install Grid Control Agent 10g, there will be no option to avoid configuration of your Metalink Access Data. But you may want to avoid this. The trick is simple: Just decline the License Agreement in the middle of the runInstaller process. The function of agent will be installed, […]