What is ora2know? One week ago, on November 18, 2024 we founded ora2know, the new German Oracle User Group. The focus of the new group is the Oracle Database and its users. If you like to participate and/or attend our meetings, please register with our newsletter! We want to do community-style meetings, one-day events, hacking […]
Pictures and Download DOAG 2024 talks
Die largest Oracle Conference in Germany is DOAG Conference + Exhibition in November. It’s always the hotspot for the whois-who in the Oracle landscape. I had the chance to present three talks one of them with Axel vom Stein, Oracle ACE Pro, working with our valued customer BSS Bohnenberg, Solingen. Talks at DOAG 2024 Three talks, all […]
Oracle Linux 8/RHEL8: Lock User After Failed Login Attempts with Faillock
Many security audits and checklists like the ones supplied by CIS or DISA STIG require locking user accounts after a number of unsuccessful login attempts. In Linux, this is usually achieved by using faillock / pam_faillock.so. Using PAM PAM (Pluggable Authentication Modules) is the flexible framework in modern Linux to customize the authentication and login […]
Database 19c Certified for Oracle Linux 9 – Preinstall Package Available
Oracle Database 19c is certified for Oracle Linux 9 now (minimum requirement RU19.19). The Oracle Database preinstall package in its initial version is also available on the public Oracle yum server, in the AppStream Repo. https://yum.oracle.com/repo/OracleLinux/OL9/appstream/x86_64/getPackage/oracle-database-preinstall-19c-1.0-1.el9.x86_64.rpm […]
Oracle gridSetup.sh Fails with Error Code 255
Bash Error 255 Sometimes you have to apply a RU when launching Oracle 19c gridSetup.sh to install Oracle Grid Infrastructure or Oracle restart. For example when you install it in its vanilla 19.3 version on Oracle Linux 8. OL8 did not exist when they made 19.3, so some of its specials (like verifying group/user existence) […]
When are Oracle RUs released? (Update)
It seems unbelievable, but sometimes Oracle REALLY simplifies things. After the rather complex calculation in the last years, now we will get new RUs on the third Tuesday of January, April, July and October. Source: https://www.oracle.com/security-alerts/ Thanks to everybody at Oracle who made this comfort possible. 🙂 Reference to old post: https://www.usn-it.de/2021/03/01/when-are-oracle-rus-released/ […]
Symposium42 // SYM42
Stay tuned, something cool in the Database World is around the corner. Symposium42 (short: SYM42) is coming soon. Follow it on Twitter: @sym_42 Why a Symposium42? SYM42 is an idea that has been discussed for a little while within a group of presenters & conference organisers, mostly based in Europe & the USA but also […]
Create Oracle Data Guard Standby with DBCA
Demands of Automation You can easily create an Oracle Data Guard Standby Database with the Database Configuration Assistant DBCA. That’s especially interesting if you have automation at work, and are not keen on configuring stuff all over the place. This is available in version 19c upwards. DBCA uses RMAN DUPLICATE FOR STANDBY with an auxiliary […]
DOAG Konferenz 2021 Slides for Download
Thank you all for attending, commenting and discussing my presentations at DOAG Konferenz 2021. I am happy about the good feedback, and the attendance in the rooms. Meeting some of you in DOAG’s GatherTown was a good thing, to mimic the real conference center in Nuremberg. But still a mimic! I’m looking forward to DOAG […]
Godspeed, Pieter van Puymbroeck
Last Sunday, I got a miserable call, one that everybody fears: On July, 16th 2021, the Oracle Community lost one of its loveliest members and a valued contributor. We all lost an amazing human being. I lost a dear and trusted friend: Pieter van Puymbroeck, you passed away in one of your favourite spots – […]
When are Oracle RUs released?
When are Oracle Release Update and Release Update Revision released? What is the schedule for RU and RUR? It’s the same as for CPU. It’s important to know that the patch cycle that produces Release Updates (RU) and Release Update Revisions (RUR) actually is the quarterly Critical Patch Update (CPU) Program for database version 12.2 […]
The Three Thirds of My Career (so far)
Recently looking into a renowned Professional Social Network, I was surprised: Somehow I managed to have three IT and Oracle jobs in sequence, and now mid-2020, all of them lasted the same amount of time. Six years and a half. 2002-2008, A.T.U Auto-Teile-Unger, where I learned to fly. 2008-2014, Klug / TGW Logistics, the lesson […]
Very cool interview with Maria Colgan
Community work can be so much fun. When working for the German Oracle User Group, DOAG, one of my favourite jobs is interviewing interesting people for doag.tv. In fall 2019, we recorded a fun interview with Maria Colgan, Master Product Manager for the Oracle Database. I had the chance to prepare the story: Based on […]
Oracle PGA Analysis Query
Sometimes, something in an Oracle Database starts eating PGA, and there is need to find out which process, and where the memory is left, and what or who is responsible for allocating / using / holding it. For a recent issue, I wrote the SQL below. It gives back one line for each Category (SQL, […]
Make Linux Disk IDs Visible for UDEV (in VMware)
VMware is a factor Times and syntaxes change, so it’s time to refresh an old blog post a bit. Especially VMware has established its place in the Oracle world, and it can be tricky to map disk IDs directly into the VM. Many sources recommend to use the SCSI addresses, but I learned to never […]
ORATOP in Oracle 19c
In 19c , the useful utility “oratop” is shipped with the Oracle Home installation. It was linked to the recent libaries, and its command line syntax changed. Error This leads to errors when calling one of the old “download” binaries like oratop12c-64.bin in a 19c environment: /home/oracle/bin/oratop12c-64.bin: error while loading shared libraries: libclntshcore.so.12.1: cannot open […]
Oracle Database 18c changed MRP checkpointing from log boundary to time-based
The gap The story started with an always-unpleasant alert log message: The reason Looking into v$archived_log: The log sequences 2306-2405 ARE applied on standby. And thus deleted by policy from the Fast Recovery Area. Okay, this explains the effect, but not the root cause. So we had to open a SR with Oracle Support. The […]
DOAG Regionalgruppe Nürnberg Anfahrt / Map
DOAG Regio und Meetup Die DOAG Regionalgruppe und Meetup Nürnberg hat ein großes Thema: Die Technologien von und rund um Oracle, und ist ganz leicht zu finden. Sie ist immer am gleichen Ort, und das Treffen findet immer am dritten Donnerstag eines jeden Monats statt (außer August und November). Die konkreten Termine und Themen werden […]
Back again!
The blog was a bit neglected over the last time. But now, with a new face and a modern backend, I’m determined to use it again. 🙂 Thanks very much Valentin and Hendrik, who did an amazing job with renewing the infrastructure and the new theme! Stay tuned! Martin […]
Oracle ACE Director
Uh, there has been no blog entry for some time, had a busy time. So now I have a good reason to blog after returning from Collaborate18 in Las Vegas, where I had the chance to present two talks about SQL Tuning and Oracle Performance on VMware. The Oracle ACE Program usually hosts a dinner […]
Oracle: Create a Materialized View with Fast Refresh on commit and debug upcoming errors
Sometimes, our users and customers need rapid access to complex data structures. Materialized Views in their various forms are a very potent way to shift efforts from the query to insert/update time of base data. That’s the nature of a Materialized View: One way or another, we need to put the data into a redundant structure. With […]
Oracle on Windows: ASM instance terminated by LMON / ORA-27300 IPC_TCPConnectCheck failed with status -1
Recently I had an issue with a two-node Grid Infrastructure on Windows 2012R2. After an infrastructure-caused cluster restart (irresponsible SAN hardware patching 🙂 ), everything was running on Node 2, and Node 1 could not join the cluster any more. No easy solution: On CSSD level, there was no issue (network and disk heartbeat worked, […]
Oracle on SLES12 SP2 – Avoiding Cgroup Task Limit
Once upon a time, there was an Oracle RAC cluster 12.2.0.1 on SUSE Linux Enterprise Server (SLES) 12 SP2, that did not do well. Its database and ASM instances used to fail with: ORA-27300: OS system dependent operation:fork failed with status: 11 ORA-27301: OS failure message: Resource temporarily unavailable ORA-27302: failure occurred at: skgpspawn3 Of […]
Oracle 12.2 sysctl.conf Default Preinstall Settings
This are the currently active settings, the oracle-database-server-12cR2-preinstall.rpm delivers on Oracle Linux 7. Maybe it’s useful for you when setting up Oracle 12.2 on SUSE / SLES where you are on your own. Maybe you also want to add Huge Pages: # Performing Databases Huge Page Settings # for SGA size 200GB and huge page […]
Oracle RAC 12.2 on SLES12 – How to disable Hardware Lock Elision Support
The Problem In the last week, I had to set up an Oracle RAC (and thus, the Clusterware) version 12.2.0.1 on SuSE Linux Enterprise Server 12 SP2 (SLES12 Sp2). The gridSetup.sh failed latest in root.sh of the first node with a kinda non-intuitive error: CRS-5804: Communication error with agent process CRS-4000: Command Start failed, or […]
Oracle RAC 12.2 High Load on CPU from gdb when Node Missing
Recently I had to battle a new issue with the quite-new Oracle Database RAC Version 12.2.0.1 on Linux x86_64. The idea of RAC is, to compensate the loss of a node or service by restarting services on other nodes. But in my case, when one node in a two-node-Cluster was down (or the crs stack […]
Restarting Oracle for Performance is like a Coitus for Virginity
Today I had another case of that … total breakdown of a live environment by infrastructure defect, bad enough. Customer rushing up the database and all apps services, just to see thousands of locks and hanging transactions. Big panic, frequent restarting of databases and applications. Getting worse, finally calling me. Told them I’ll manage that, asked […]
Oracle RMAN destination with variable restrains “not backed up” clause
Today I was a bit surprised – being always under the impression that Oracle RMAN should accept “backup backupset not backed up to destination ‘xyz’” AND work with it successfully. But I learned that in 11.2.0.4 the Oracle RMAN “to destination” containing variables restrains the “not backed up” clause. No error thrown, but just does not work […]
Oracle Database 12.2 on-premises release dates
Oracle recently announced the availability of Oracle Database 12c release 2 (12.2) for on-premises servers. https://www.performing-databases.com/en/2017/01/oracle-database-12-2-on-premises-release-dates/ Linux x86-64, Solaris SPARC and Solaris x86-64: 15-Mar-2017 Other supported platforms (Windows x86-64, IBM AIX on POWER, IBM Linux on System z, HP UX Itanium): Q2CY2017 Source: MOS DOc ID 742060.1 […]
Oracle Enterprise Linux 7: How to stop bash tab completion from escaping the dollar $
Did you ever wonder why bash in Oracle Linux, Red Hat Enterprise Linux and other recent Linuxes escapes the dollar sign ($) when completing paths with the tabulator (tab) key like that: [oracle@oratest01 ~]$ (KLM12102) ls -l \$ORACLE_BASE/diag Answer In bash >= 4.2.29 you have a “direxpand” option, which is NOT set by default. The […]
Oracle: How to identify SQL doing TABLE ACCESS FULL on a given partition
In my last post, I described a quick show case for Oracle 12c Automatic Big Table Caching. But ABTC is just a crock, nevertheless a useful one. The biggest help from Automatic Big Table Caching for “sustainable” database performance management is the temperature of segments, heated up by TABLE ACCESS FULL. In my case, after enabling ABTC […]
Oracle Automatic Big Table Caching – an improvement, not a fix
Too much TABLE ACCESS FULL in your Oracle Database? Thus, SQL elapsed time too slow for the demand? Plenty of Buffer Cache to create a temporary fix? maybe you want to consider Automatic Big Table Caching. Usually, Oracle only does Full Table Caching for small tables. Big ones will only use the Buffer Cache for the current chunk […]
Oracle 11g unable to extend datafile but ASM disk group shows free space
Sometimes Oracle Database 11gR2 complains about not being able to extend a (lob) segment with ORA-1691, but ASM monitoring based on USABLE_FILE_MB did not fire. Adding a new data file fails with ASM ORA-15041. I was under the impression this behaviour of ASM deserved some explanation. Situation Database Alert Log complains with ORA-1691: ORA-1691: unable to extend lobsegment MYUSER.SYS_LOB0013128030C00003$$ […]
My COLLABORATE16 look-at’s – an aftermath
From April 10th to April 14th 2016 many Oracle professionals congregated in Las Vegas. The three big U.S. user groups, the IOUG, the OAUG and the Quest User Group once again formed one of the best Oracle Conferences in the world: COLLABORATE16. I was honored to be there as a speaker, and glad to perform […]
Oracle SQL showing current expensive queries plus most expensive object from execution plan
Sometimes, it’s useful to see what’s currently going on in your Oracle Database. This query is meant to help with this task, that haunts every DBA from time to time. It’s just using v$sql and v$sql_plan, so no need for Enterprise Edition and Diagnostics Pack. Key features: find top buffer getters per execution from v$sql […]
Looking forward to speaking at COLLABORATE16 IOUG Forum
Yes, I did it again, submitted and got two papers accepted – speaking at COLLABORATE16 in Las Vegas (#C16LV) is always a highlight of the year! This time, it will be: The Bad One In Your Crop – SQL Tuning Analysis For DBAs 4:30 PM–5:30 PM Apr 11, 2016, Palm-A Oracle Core: 12c InMemory Column […]
Featured by Oracle Magazine
The Oracle Magazine featured me in its January / February 2016 issue. I really feel honoured and would like to say thank you for the opportunity! For details, please see the Performing Databases Blog post about the publication. […]
DOAG noon2noon RAC & Dataguard – Quick Report
There’s always something to learn – for example about Oracle RAC (Real Application Clusters) and Dataguard. And the old-school frontal teaching concept is boring, and more important, ineffective after a few hours of passive listening. So the German Oracle Users Group DOAG organized a “noon2noon” event: “Oracle RAC and Dataguard” this week in Würzburg (January 2 1st-22nd 2016). It was the […]
How to disable Oracle ACFS drivers / registry resource
Sometimes an installed ACFS can cause trouble, especially if we don’t or can’t use it (e.g. when not using an UEK Linux kernel, like with SuSE Linux Enterprise Server SLES). There’s lots of documentation how to create and maintain ACFS file systems, but how to get rid of ACFS at all wasn’t so easy to […]
Oracle 11g and 12c Cardinality Feedback Leads to Hundreds of Child Cursors
Sometimes, advanced features can bring advanced problems. Seeing a project with hundreds of child cursors with a different execution plan each, is never a pleasure, but there has to be a reason. In fact, we are talking about the “USE_FEEDBACK_STATS” reason in v$sql_shared_cursor. Its meaning is: “A hard parse is forced so that the optimizer can reoptimize […]
What is a “RAC Battle”?
RAC Battle [ræk ˈbæt̬l̩] What is a “RAC Battle”? It is a format of presenting technology – two experts, battling against each other on pros and cons of Oracle Real Application Cluster. Björn Rost (Oracle ACE Director) and Martin Klier (Oracle ACE) will fight Wednesday November 18th, 2015 11 am Nürnberg CCN (DOAG Konferenz 2015) […]
Oracle Database 11.2 Extended Support Waived
As announced today, Oracle waived the Extended Support for the period of February 2015 until May 2017. See the paper with details here. […]
Oracle 12c in practice – customer report in Cologne #12cjetzt
From Beta to Production – Oracle 12c at TGW In October, I’ll speak at the Oracle #12jetzt (#12cnow) symposium in Köln (Cologne) about the introduction of 12c as standard palttform at our ISV customer TGW Software Services. I had the privilege to continuously working on the 12c product evaluation and introduction from availability of 12c beta2 […]
Oracle dbms_workload_repository awr_global_report_text fails with ORA-06553 PLS-307
My last post was about generating AWR reports from SQL – not a very complicated case. “But” – little word, big meaning. And suddenly we get a strange error message. In my example, I was especially interested in a Real Application Cluster’s “global” report. The subprogram call for that purpose is dbms_workload_repository.awr_global_report_text(), accepting the DBID, begin […]
How to create an Oracle AWR report with SQL and PL/SQL
AWR is a great tool (but needs diagnostics pack). It can create very useful reports for performace analysis over a given period. Most people will pull the AWR Report from the OS level, with ‘@?/rdbms/admin/awrrpt.sql” (or one of the other scripts there). But sometime it’s not possible to access a database server’s OS level, or […]
Oracle 12c RMAN delete obsolete behaves interactively in DBMS_SCHEDULER job type BACKUP_SCRIPT
Situation In Oracle Database 12c, we have the long-missed feature of DBMS_SCHEDULER job type “BACKUP_SCRIPT”, that allows us to create backup jobs without creating them as an OS file, and without need for a wrapper script that’s called by a job type EXECUTABLE (as we usually did that in the last years). Sometimes we also […]
DOAG Database Conference 2015 begins #DOAGDB15
It’s time! June 16th, the DOAG Database Conference takes place in Düsseldorf, Van Der Valk Airport Hotel. Twenty-two specialized talks about Oracle Database, Replication, Tools and Security promise a great techie-day. See the schedule of lectures here. I’m looking forward to seeing you there, having great corner talks about Oracle, life and lemons, tweeting with […]
DOAG BI Conference: Oracle Core (for Beginners): In-Memory Column Store
On Thursday, April 23rd I’m speaking at DOAG BI 2015, the leading Oracle Business Intelligence Conference in Germany. (#DOAGBI15) My contribution is: “Oracle Core für Einsteiger: In-Memory Columns Store”. The lecture will show, how the Oracle Database In-Memory option works “under the hood”, and how it is used to the best effect. Please find the presentation […]
Chemnitzer Linux Tage 2015
Last weekend, I had the chance to attend the Linux Days Chemnitz. It’s an annual meeting of the German Linux family with roundabout 2,500 attendees and a FANTASTIC atmosphere. It was two days of hearing tech talks, enjoying rich nerd content and talkin’ shop. […]
Martin Klier Oracle ACE
I feel VERY proud, honoured and grateful, that Oracle awarded me with the Oracle ACE in December 2014. The Oracle ACE program is a community reward, and encourages us to participate, enrich, promote and organise Oracle community events. When speaking about the community, first of all I’d like to highlight my Oracle User Group of Germany, […]