ASM
24.02.2015

Oracle ASM

There is some kind of wrong understanding, regarding what Oracle ASM really is. A lot of people thinks, that this is some kind of file system, provided by Oracle and that Oracle Database reads data "from ASM", while the truth is, that the database reads data directly from the physical raw device with assistance of […]


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12c
09.02.2015

12c: New "small" features: DBCA

There are a lot of new powerful features in the 12c database but don’t forget about the little features that can make a DBA happier on the day to day basis 🙂 One of my favourites is a new approach to use a DBCA command line interface to create a database in silent mode: Nice, […]


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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 http://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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