SECURITY
28.01.2015

Oralce uses gethostbyname in "*skgxp*" libraries [CVE-2015-0235]

Recently there was a new vulnerability introduced in glibc library: http://www.openwall.com/lists/oss-security/2015/01/27/9 Oracle is using the gethostbyname function in "*skgxp*" libraries: So this can be an issue – a specially in RAC environments. RedHat recommends to upgrade the glibc libraries: https://access.redhat.com/articles/1332213 And I do agree 😉


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12c
27.01.2015

Slow TRUNCATE TABLE due to operations on MON_MODS$

One of my customers had a problem with a very slow TRUNCATE TABLE operation on a partitioned table having 22 000 partitions. The problem has raised after a test migration to database 12c. I’ve prepared a little demo to address this issue and show the walkaround for it. Oracle Database 12c (12.1.0.2): Oracle Database 11g […]


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SECURITY
23.12.2014

Simple technics of privilege escalation — part2: DBA=SYSDBA

A lot companies consolidates databases into one appliance – like for example Oracle Exadata. So you can have a lot of different databases in one physical cluster. And what if I tell you that you can execute any OS command as an oracle user, having just access to a database user with appropriate privileges? What […]


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CONFERENCE
06.12.2014

dBConf 2014

Ludzie z PLUG (http://www.linux.org.pl/) zorganizowali w tym roku pewną wyjątkową konferencję – dBConf (https://www.dbconf.pl/2014/pl/) pod hasłem "Bazodanowcy wszystkich środowisk łączcie się!". Idea zacna i mam nadzieję, że zyska popularność na polskiej scenie konferencyjnej, bo jak często się zdarza, żeby Oracle’owiec pogawędził przy piwku ze specem od DB2 lub SQL Server’a? Wymienił się uwagami z fanem […]


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TUNING
10.10.2014

Oracle 11g & 12c: tunning the sort and hash operations

Hash and sort operations are perfomed in PGA. Quoting after the documentation: A sort operator uses a work area (the sort area) to perform the in-memory sorting of a set of rows. Similarly, a hash-join operator uses a work area (the hash area) to build a hash table from its left input. If the work […]


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12c
27.09.2014

Oracle 12c: Oracle ASM Filter Driver (AFD)

In Oracle 12c (12.1.0.2 to be exact) we can find a cool new feature: Oracle ASM Filter Driver. Quoting after the documentiation: Oracle ASM Filter Driver (Oracle ASMFD) is a kernel module that resides in the I/O path of the Oracle ASM disks. Oracle ASM uses the filter driver to validate write I/O requests to […]


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RMAN
15.09.2014

Restore all versions of the spfiles

A few months ago I showed how to restore a controlfile, when you have no idea in which backupset is the newest file https://blog.ora-600.pl/2014/04/26/oracle-myth-you-need-dbid-to-restore-the-controlfile/ On last training one of my students asked me, how to locate an appropriate spfile backup after using this trick (the restored database has a different DBID). Well, you can just […]


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TOOLS
10.09.2014

Script for metadata export in SQL*Plus

Sometimes you have to export all metadata for a schema but you have no access to data pump or other tools. SQL Developer can cause a lot of problems with referential constraints. But there is always a good old SQL*Plus 🙂 http://ora-600.pl/oinstall/metadata.sql


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INTERVIEW
26.08.2014

Interview for "IT Certification Master"

http://www.itcertificationmaster.com/become-oracle-certified-master-fun-profit-kamil-stawiarski/


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12c
17.06.2014

Oracle 12c – WITH FUNCTION

In Oracle 12c there is a possibility to define a PL/SQL function inside the "WITH" clause, which can reduce the context switching overhead. Short example:


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RAC
16.06.2014

HOWTO: Install Oracle RAC 11gR2 on VirtualBox (OEL6.4)

Install Oracle RAC 11gR2 on VirtualBox: http://www.youtube.com/playlist?list=PLqQNL6H71xCygSF_VqwM8j-Hhft4XoEEx VM templates can be found here: https://mega.co.nz/#!esp1kQQA!CUr8SlErdPppk-GkxedTUAdMpVQPrrrSI3c1ouquAhk Prezi: Route to install simple RAC


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RAC
16.06.2014

Oracle RAC 11.2.0.4 – add another ethernet to interconnect

Instead of bonding you can use Oracle cluster interconnect HAIP for using multiple ethernets. And here is how its done 🙂 At the begining I have one interconnect – eth1: To add another one (eth3), I will use an oifcfg tool: Now the restart of the CRS on all nodes is required for changes to […]


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12c
11.06.2014

Oracle Database 12c new features (Data Guard & RMAN)

Moja prezentacji z konferencji COIG http://prezi.com/ov5xbjytuzgw/?utm_campaign=share&utm_medium=copy&rc=ex0share


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EXADATA
07.05.2014

Exadata – skgxpinfo returns UDP after reconfiguration

We had to change the hostnames on Exadata with one of the customers. It is a well known fact that RAC doesn’t like such changes – we had to reconfigure the cluster and after the whole process I found the funny thing: So let’s try to turn RDS on 🙂 After shutting down all cluster […]


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12c
26.04.2014

Oracle 12c – FETCH FIRST n ROWS ONLY

Oracle 12c offers a lot of fascinating new features – among them (at last) "FETCH FIRST n ROWS ONLY" syntax. http://www.oracle-base.com/articles/12c/row-limiting-clause-for-top-n-queries-12cr1.php Out of curiosity I’ve checked with 10053 event, the following query: And this was the result 🙂


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RMAN
26.04.2014

Oracle myth: You need DBID to restore the controlfile

My experience shows that you don’t have to know the DBID now for restoring contorlfile from backup. If I know the name of backup piece, that contains controlfile I can do the following scenario: If I don’t know the name of the backup piece and there is a lot of strangely named files in a […]


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TUNING
26.09.2013

Oracle CBO. Query Transformer

Oracle Cost Based Optimizer consists of three main components: Query Transformer, Esitmator, Plan Generator. In this article I will try to show you some interesting features of the first component – Query Transformer. This component has some very powerful features and most of them remain in shadows, unrevealed while other new features gains all the […]


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ENTERTAINMENT
12.06.2013

InfoShare-oracle-hacking-session

Tak dobrych referencji jeszcze chyba nigdy nie dostałem 🙂 I gdybym cechował się jakąkolwiek skromnością, to bym tego nie publikował. http://rafalosinski.com/lifetech/najlepsza-znana-mi-prelekcja-czyli-warsztatu-z-hackowania-oracle-na-infoshare/


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