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Investigating the full table direct path / buffered decision. | Frits Hoogland Weblog
https://fritshoogland.wordpress.com/2015/06/29/investigating-the-full-table-direct-path-buffered-decision
IT Technology; Oracle, linux, TCP/IP and other stuff I find interesting. June 29, 2015. Investigating the full table direct path / buffered decision. Alter session set events 'trace[nsmtio]';. Nsmtio: non smart IO). 1 Table too small for direct path read. TS@v12102 alter session set events 'trace[nsmtio]'; Session altered. TS@v12102 select count(*) from smalltable; COUNT(*) - - - - - 1000000 TS@v12102 alter session set events 'trace[nsmtio] off'; Session altered. Type 2: oracle’s internal database ...
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Hey dude, where’s my memory? part 2 | Frits Hoogland Weblog
https://fritshoogland.wordpress.com/2015/04/08/hey-dude-wheres-my-memory-part-2
IT Technology; Oracle, linux, TCP/IP and other stuff I find interesting. April 8, 2015. Hey dude, where’s my memory? In my previous article. I started exploring the memory usage of a process on a recent linux kernel (2.6.39-400.243.1 (UEK2) , recent means “recent for the Enterprise Linux distributions” in this context, linux kernel developers would point out that the kernel itself is at version 3.19 (“stable version” at the time of writing of this blogpost). The columns that show information on memory ar...
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Using the Oracle Grid Infrastructure Agents for GoldenGate on Oracle restart | Frits Hoogland Weblog
https://fritshoogland.wordpress.com/2015/03/30/using-the-oracle-grid-infrastructure-agents-for-goldengate-on-oracle-restart
IT Technology; Oracle, linux, TCP/IP and other stuff I find interesting. March 30, 2015. Using the Oracle Grid Infrastructure Agents for GoldenGate on Oracle restart. I was testing Oracle Goldengate on a non-clustered Oracle 12.1.0.2 database with ASM. With ASM, you need to have the grid infrastructure installed. The cluster ware for the single node install is called ‘oracle restart’. The control utility, ‘agctl’ can be run without any environment variables set to point to the directory where...U01/app/o...
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Extra huge database IOs, part 3 | Frits Hoogland Weblog
https://fritshoogland.wordpress.com/2013/07/14/extra-huge-database-ios-part-3
IT Technology; Oracle, linux, TCP/IP and other stuff I find interesting. July 14, 2013. Extra huge database IOs, part 3. This is part 3 of a number of blogposts about huge Oracle database IO’s. If you landed on this blogpost and did not read part 1 or part 2, please read part 1 here. And part 2 here. With all the gained knowledge, the next thing I ask myself is: how did Oracle implement this? What operating system calls are done? The obvious answer is take a peak! After the above mentioned initial operat...
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Oracle 12 and latches, part 2 | Frits Hoogland Weblog
https://fritshoogland.wordpress.com/2015/07/17/oracle-12-and-latches-part-2
IT Technology; Oracle, linux, TCP/IP and other stuff I find interesting. July 17, 2015. Oracle 12 and latches, part 2. In my previous post. I looked at non shared latches and how the latching is done by Oracle. This post is a description on how the latching works for shared latches. The information is quite internal, if you landed on this page it might be a good idea to start with my first post on this topic: first post. A famous example for shared latches is the ‘cache buffers chains’ latch. I essential...
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Oracle 12 and latches | Frits Hoogland Weblog
https://fritshoogland.wordpress.com/2015/07/17/oracle-12-and-latches
IT Technology; Oracle, linux, TCP/IP and other stuff I find interesting. July 17, 2015. Oracle 12 and latches. Oracle DBAs who are so old that they remember the days before Oracle 11.2 probably remember the tuning efforts for latches. I can still recall the latch number for cache buffers chains from the top of my head: number 98. In the older days this was another number, 157. Luckily, I could get a great headstart by studying the work of Andrey Nikolaev. I decided to take a look on how this works on Lin...
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Using udev on RHEL 6 / OL 6 to change disk permissions for ASM | Frits Hoogland Weblog
https://fritshoogland.wordpress.com/2012/07/23/using-udev-on-rhel-6-ol-6-to-change-disk-permissions-for-asm
IT Technology; Oracle, linux, TCP/IP and other stuff I find interesting. July 23, 2012. Using udev on RHEL 6 / OL 6 to change disk permissions for ASM. When you use Oracle ASM (Automatic Storage Management) for your database, the permissions on the block devices on the operating system layer which are used by ASM need to be changed. To be more precise, the owner and group need to be set to ‘oracle’ and ‘dba’ ( Oracle documentation. The linux system has functionality which equals the block device generati...
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Throttling IO with Linux | Frits Hoogland Weblog
https://fritshoogland.wordpress.com/2012/12/15/throttling-io-with-linux
IT Technology; Oracle, linux, TCP/IP and other stuff I find interesting. December 15, 2012. Throttling IO with Linux. I guess the first question which comes to mind when reading this title is ‘Why’? I think that if you combine the ‘disk getting faster’ effect with the need to investigate IO’s, you understand that it can be beneficial to throttle IO’s in certain cases. Simple setup and usage. First, we need to make sure the ‘blkio’ controller is available:. In order to throttle IO on the device, we need t...
