RICO
31.07.2016

how to recover dropped package

Sometimes you drop something by accident – you know, the syndrome called "An Enter Too Far". If you drop a table, the case is easy – you can use recyclebin to restore it. But when you drop a package or procedure… well, you have a problem Of course, you could use a flashback query on […]


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AWK
27.07.2016

AWK TO THE RESCUE 3 – match ASMLib with multipath

This will be just short article with very simple trick, showing how to match the ASMLib devices with actual multipath devices. I’m sure there is a simpler way… but I just love using AWK If you know a simpler or more elegant solution – please post it in the comments section. My solution looks like […]


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RAC 12c
14.06.2016

ORACLE RAC 12c: restore OCR and VOTEDISK

Let’s fuckup the cluster! Of course after this operation, the final state of the processes can look like this: The cssd service will not be able to start, because there are no voting disks: OK, so let’s try to stop the cluster services: Now we will have to start CRS in exclusive mode and start […]


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opifch2
27.05.2016

Context switch – PL/SQL cursor loops and fetchsize vs opifch2

Well it has been a month since my last blog post, so I think it’s time to write something Those context switches can be a real pain in the ass – there is a great article by Frits Hoogland about context switching from SQL to PL/SQL – you can read it here: https://fritshoogland.wordpress.com/2016/01/23/plsql-context-switch/ You should […]


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Exadata & SR-IOV
26.04.2016

Infiniband SR-IOV on Exadata OVM

Virtual hosts on Exadata with OVM are HVM and not PV. This is one of the limitations of Infiniband SR-IOV – can’t be used with PV. So there is a qemu used to emulate the hardware While accessing a physical device from within a DOMU we can see that actual work is being done on […]


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EXADATA+OVM
03.04.2016

Exadata & OVM: Unable to get map of the virtual network interfaces

This week I had a "pleasure" of reimaging Exadata server to use OVM. During this process we hit interesting problem – after the reimaging process there was no bridge at DOM0, corresponding to the client network – because of this, the OEDA sofware returned an error like this: The error was produced by this script: […]


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AWK
16.03.2016

AWK to the rescue 2 – 10046+10053 = ?

I’ve created recently a script in AWK to create wait event histogram from 10046 trace file. The script can be found here. I thought that a good idea would be creating a little script to analyze the contents of 10053 and 10046 events together. So I wrote one You can download it here: http://ora-600.pl/oinstall/format_10046_10053.awk How […]


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AWK
08.03.2016

AWK to the rescue – wait event histogram from trace file

I wrote a very simple script in AWK to create wait event histogram (for db file scattered read, db file sequential read, direct path read and direct path read temp) based on 10046 trace file with wait events. Maybe someone will find it useful The sample output looks like this: Enjoy 😉


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#oug_ire
07.03.2016

OUG Ireland 2016

I was second time at the conference organized by UKOUG but this time I had a pleasure to be among the speakers To reach the level set by other speakers was impossible – but trying it gives a lot of fun. Since I did a live demo and I didn’t have any slides – I […]


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EXADATA
11.02.2016

Exadata – direct path write temp and flash disks

Some time ago one of my students asked me if temp segments are being written to flash disks on Exadata… Well I wasn’t sure But recently I had some time to check it. Let’s create some query that will generate temp segment: Great. Now we have to do some tracing at the cell servers level. […]


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12c & external tables
10.02.2016

How to list files from directory using external table in 12c

I’ve wrote about privilege escalation with external tables in this post: http://blog.ora-600.pl/2014/12/23/simple-technics-of-privilege-escalation-part2-dbasysdba/ This time we will try to list all files within directory object, to which we have no EXECUTE privs. This is possible due to great new feature of database 12c that allows to use metacharacters to match multiple files in external table. I […]


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M7
08.02.2016

Sparc M7 vs Intel and P8

I had a pleasure to work with my colleagues from Oracle – Radosław Kut and Krzysztof Marciniak – at comparing the performance of In-Memory queries between Sparc M7, Intel® Xeon® X5670 and Intel® Xeon® E5-2699. You can find results of our findings in this presentation: https://www.oracle.com/webfolder/s/delivery_production/docs/FY16h1/doc17/DB12c-on-SPARC-M7.pdf Following their methodology I’d like to present appropriate results […]


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