Archive for the 'Oracle' Category

Oracle 12c InMemory – don’t stop thinking about performance

Oracle has released its new database version that includes the famous in-memory column store. InMemory option  promises a big advantage for OLAP-like work loads by keeping table contents in a columnar in-memory structure. InMemory is not new, they did that for decades, but the interesting part is “columnar”. There’s much writing about that on the net and in the Oracle Concepts Guide, no need to reproduce that here.

But though the new feature is very young, we already can see a “you can stop using your brain, we have a new catch-them-all feature” thinking, at least such a marketing sound. But it’s quite easy to show that this is not real. As for many other features we got over the years, using Oracle InMemory still needs a concept, done by an architect knowing the ups and downs.

What I can see from playing with Oracle Inmemory is, that it’s only beneficial when all data you (might) have to query from is already in the columnar cache (Oracle term is “populated”). If not, query response times don’t improve much. Let me show you my test case.

Read more…

Oracle with In Memory Option available for Linux

As of today, the Oracle Database with InMemory Columnar Store is available at


According to the price list of July 10th, it will be sold as an option for Enterprise Edition (Exadata NOT mandatory), for US$ 23,000 per CPU (calculation like EE).

Hope it will do well, beta demos were extremely impressive.


Oracle Core für Einsteiger: Datenbank I/O at DOAG 2014

Proud to announce, that DOAG accepted my tech talk “Oracle Core für Einsteiger: Datenbank I/O” for DOAG Conference 2014 in Nuremberg. It’s my next contribution to DOAGs thread aiming at beginners and part-time database people.


The talk will be in German, here comes its abstract:

Oracle Core für Einsteiger: Datenbank I/O
Wir kennen verschiedene I/O-Typen, die die Datenbank benutzt um ihre Aufgaben zu erfüllen. Der Vortrag zeigt anschaulich wie sie sich unterscheiden, und erklärt, welche Vorteile die einzelnen Methoden bieten. Behandelt werden Zugriffe auf Tablespaces, Online/Archived Redo Logs und verschiedene Dateitypen, die mit der Instanz in Verbindung stehen. Eingeschlossen ist eine kurze Wiederholung der jeweiligen Funktion im RDBMS; ebenfalls enthalten ist ein “Crashkurs” zum Automatic Storage Management “ASM”.

Das Ziel des Vortrags ist, Einsteigern das Verständnis von Massenspeicheroperationen näher zu bringen und Hintergrundwissen für ein kompetentes Storage-Sizing zu vermitteln.

I’m also very happy to announce, that my business partner Benedikt Nahlovsky‘s presentation “Kostenlos aber effektiv: Performanceanalyse mit Statspack und SQL*” also was accepted. It’s all about doing professional performance analysis with STATSPACK and SQL* tools.

So Performing Databases is present with two sessions, we really appreciate it!

Looking forward to seeing you all at CCN East, Nuremberg Trade Fair, 18th-20th November 2014!

Stay safe
Martin Klier

Oracle SQL Developer: New window, new session. Bad behavior?

Yay, it’s there. SQL Developer 4 is usable. It brings a new session for a new window (“unshared worksheet” in Oracle terms) – I was told lately SQL Developer 3 already had this. Did you know? Now we are kind of stable in 4: The 4.0.2 build 1521 (hehe) works good, so it’s time to see how “Unshared Worksheet” works here. That’s what we alwas had – one sheet, one session:

That's what we alwas had: One sheet, one session


Read more…

Oracle 11.2 PSU2 Grid Infrastructure stack start … failed to complete at line 11814

Oh, sometimes it’s just (own or close-people’s) PEBKAC that costs you time and gray hair… Patching to PSU2 on Linux was such an issue.


“opatch auto” with all comfort worked well, applied the patch, but re-starting the clusterware failed with:

Starting CRS... 
Installing Trace File Analyzer 
CRS-4123: Oracle High Availability Services has been started. 
Oracle Grid Infrastructure stack start initiated but failed to complete at 
/u01/app/11.2.0/grid_2/crs/install/ line 11814.

What happens here? OHASD tries to start up CRSD, but it fails with an exception: permission check failed. Mh, might come from most $GRID_HOME/bin/*.bin files have no executable (“x”) flags set. WTF?
So what.. who’s the culprit? Spent a whole weekend on investigating and re-trying, just to learn that the scripts in the PSU won’t change a flag in bin directory. What do the file parameters look like in the unzipped patch directory. The same. Grml.

Wait… The PSU2 README.html says: “unzip the patch as the grid home owner”. How did the patch directory get to the server…? Oh yes, it was unzipped on the downloading machine (automatically). Woe …


  1. Download the PSU in zipped format
  2. Copy the ZIP container to the system you’d like to patch
  3. “Unzip the patch as the grid home owner”
  4. Don’t find a “failed to complete at line 11814″ in your console output
  5. Have an early beer for reading correctly, and not a late one for finding your own mistakes

Be an extremely careful reader and stay safe

Oracle on Linux: How to hide your password when using a wrapper script

Sometimes, a DBA has to write an externally called wrapper script for various Oracle-supplied commands accepting password inputs. A prominent and simple example is SQL*plus (sqlplus).

The Problem

The process list shows all parameters of a command that’s currently executed.

Accepts all connection infos on the command line:

 cmdstring="sqlplus ${1}/${2}@${3}"
 echo "Executed command: $cmdstring"
 sleep 999

Called by:

$ ./ system manager mydb
 Executed command: sqlplus system/manager@mydb

But now, the password is visible in the process list:

$ ps aux | grep | grep -v grep
 1000     20769  0.0  0.0  13808  1444 pts/1    S+   15:19   0:00 /bin/bash ./ system manager mydb Read more...

Slides for COLLABORATE 2014 IOUG forum talk #C14LV

Hi folks,

here’s my slides for “YOUR machine and MY databases – a performing relationship?!” at Collaborate 2014 Las Vegas. Any feedback is greatly appreciated!




Some pictures to come soon!

You may want to follow the #C14LV hashtag to see what’s going on. :)


DOAG Würzburg: “Resolving child cursor issues resulting in mutex waits”

I feel honored that DOAG asked me once more for being a speaker at an event – this time it’s DOAG Regionalgruppe Würzburg. I will give my (updated) C12LV and Oracle Open World 2012 talk “Resolving child cursor issues resulting in mutex waits” there, supported by my new business Performing Databases GmbH.

My abstract:
In special situations, the Oracle Database generates too many child cursors for particular SQL-IDs. This results in high CPU load on the DB server, coming from heavy mutex access. This is visible as mutex wait events. The lecture will show how this situation arises, how the DBA can try to quick-fix it and how long-term solutions can be found. Additionally, we will have a closer look on the Oracle internal situation: Why does the DB use mutexes here, and how?

Thursday (Donnerstag) 27.03.2014
5 p.m. (17 Uhr)

Würzburger Versicherungs AG
Bahnhofstraße 11
97070 Würzburg

The presentation will be available after the talk at and on the DOAG online-resource page.

Oracle Dataguard: ORA-00600 [krsu_upi_atc.7] – crash when primary ships the first time

After setting up a new Oracle Dataguard system (primary plus one standby DB), everything looked promising.

But after activating the log shipping from primary, and after archiving a redo log for the first time, the primary instance crashed with ORA-00600 [krsu_upi_atc.7]. Without the standby system available (DB idle or listener off), no error occurred.

 LGWR: Setting 'active' archival for destination LOG_ARCHIVE_DEST_2
 LGWR: Archival destination is a Primary RAC instance: 'ITWMT2'
 Errors in file /u01/app/oracle/diag/rdbms/itwmt/ITWMT/trace/ITWMT_lgwr_22151.trc  (incident=18089):
 ORA-00600: internal error code, arguments: [krsu_upi_atc.7], [], [], [], [], [], [], [], [], [], [], []
 Incident details in: /u01/app/oracle/diag/rdbms/itwmt/ITWMT/incident/incdir_18089/ITWMT_lgwr_22151_i18089.trc
 Use ADRCI or Support Workbench to package the incident.
 See Note 411.1 at My Oracle Support for error and packaging details.
 Errors in file /u01/app/oracle/diag/rdbms/itwmt/ITWMT/trace/ITWMT_lgwr_22151.trc:
 ORA-00600: internal error code, arguments: [krsu_upi_atc.7], [], [], [], [], [], [], [], [], [], [], []
 LGWR (ospid: 22151): terminating the instance due to error 470
 Wed Mar 19 15:27:07 2014
 ORA-1092 : opitsk aborting process
 Wed Mar 19 15:27:07 2014
 System state dump requested by (instance=1, osid=22151 (LGWR)), summary=[abnormal instance termination].
 System State dumped to trace file /u01/app/oracle/diag/rdbms/itwmt/ITWMT/trace/ITWMT_diag_22141_20140319152707.trc
 Dumping diagnostic data in directory=[cdmp_20140319152707], requested by (instance=1, osid=22151 (LGWR)), summary=[abnormal instance termination].
 Instance terminated by LGWR, pid = 22151

Instance terminated by LGWR did not look promising. Plus no search-engine-of-choice hits, no MOS search result. But re-reading the configuration unveiled a very basic mistake: The DB_UNIQUE_NAME of the two databases (primary and standby) was the SAME – not exactly the purpose of a UNIQUE name…. Changing it on standby side, and off it went.

Let me tell you, read carefully.
Martin Klier

DOAG Database Conference Düsseldorf: “YOUR machine and MY database” was accepted

DOAG just informed me that my talk, “YOUR machine and MY database – a performing relationship!?” was accpeted for DOAG Database Conference Düsseldorf. Last year, the first Database Conference at Düsseldorf was a great success, I enjoyed it very much. I’m glad to be part of the speaker’s corps this year.

Hope to see you there!

June 3rd, 2014
Van der Valk Airport Hotel





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