Category Archives: Miscellaneous Oracle

Miscellaneous Oracle

Oracle 12c, big table caching

Posted on October 3, 2016 by mgogala

In Oracle 11g,  there has been annoying change which has frequently had a seriously detrimental effect to the application performance. All tables, larger than 2% of SGA, were considered big tables and were read using direct reads into PGA, instead … Continue reading →

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Missing Information

Posted on November 18, 2013 by mgogala

Since the version 11G it is possible to exclude committed blocks from specific tablespace from being written to flashback recovery area. FBDA process writes committed blocks to flashback area and is quite IO intensive. There are, among other things, flashback … Continue reading →

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Expert consolidation in Oracle database 12c

Posted on March 25, 2013 by mgogala

Today, I entered the term “Oracle Database 12c” in the books section of Amazon.com, my favourite, and was surprised by the results. There are few books announced for April 2012, some for May and June 2013, without the database even … Continue reading →

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The Case of Missing Utility

Posted on February 25, 2013 by mgogala

Recently, I’ve asked to help a client who was having doubts about their backup strategy. The client was considering image backup of database which would be constantly recovered and backed up to tape on the daily basis, by using “backup … Continue reading →

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ASM, block devices and SCSI emulation.

Posted on February 18, 2013 by mgogala

Quite recently, I learned that Oracle ASM is now supporting blockdevices. The whole process is described here: http://docs.oracle.com/cd/E11882_01/install.112/e17212/storage.htm#CDEBFDEH This deserves few additional observations. The main engine that enablesone to add block devices to SCSI is udev. Essentially, one creates SCSIdevices … Continue reading →

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Native PLSQL Execution

Posted on January 27, 2013 by mgogala

Native PLSQL execution has changed significantly since the version 10G. The effects are less than spectacular, in the ideal case I got about 10% of the performance boost. This is much easier to administer now, there are no shared libraries … Continue reading →

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Native Compilation and TRCA

Posted on January 25, 2013 by mgogala

Carlos Sierra of Oracle Corp.  created a very useful tool called TRCA, intended for analyzing Oracle trace files, much like tkprof. The tool is written entirely in PL/SQL, so there is no command line interface distributed with the tool. It … Continue reading →

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