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 […]
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 […]
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 […]
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 […]
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
http://www.itcertificationmaster.com/become-oracle-certified-master-fun-profit-kamil-stawiarski/
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:
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
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 […]
Moja prezentacji z konferencji COIG http://prezi.com/ov5xbjytuzgw/?utm_campaign=share&utm_medium=copy&rc=ex0share
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 […]
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 🙂