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Stefan Koehler Profile
Stefan Koehler

@OracleSK

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Following
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Independent Oracle performance consultant and researcher. Internals geek. OakTable member. Oracle ACE Alum. Sym42.

Bavaria, Germany
Joined October 2014
Don't wanna be here? Send us removal request.
@OracleSK
Stefan Koehler
7 years
🛑 2019 Is The Time For New Oracle Support/Troubleshooting Ways 🛑 • Tired of buying a huge contingent from a consultancy if you just want a few hours or days? • Tired of ticket/service request ping pong? • Wanna get to root cause quickly? I have the solution for you 🤓
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@chris_skyflier
Christoph Lutz
8 months
lgwr: You have the control gdb: I have the control
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@OracleSK
Stefan Koehler
8 months
NOPs and shifting trampolines is a fun on-going story all the time (e.g. 2-byte NOP, 0x66 prefixed and eBPF) 🤓 https://t.co/OiODvYiooX
blogs.oracle.com
An insight to kernel tracing and its interaction with ksplice.
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@chris_skyflier
Christoph Lutz
8 months
If you've ever felt the need to manually control adaptive lgwr features, this gdb script's got you covered: https://t.co/d3AZIDjlYN 😎 It lets you enable and disable adaptive scalable lgwr, fast log file sync, and log parallelism. Highly experimental, of course! Example 👇
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@OracleSK
Stefan Koehler
9 months
Hallo @Hosteurope Für was gibt es bei Euch das KIS, wenn Ihr dort sowieso keine geplanten Wartungen mehr ankündigt oder Störungen ver��ffentlicht?
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@OracleSK
Stefan Koehler
9 months
Any reason why the OVA image of the Oracle Database Free 23.x Virtual Appliance is not updated anymore? 23.8 is out for quite a time now but the OVA image is still 23.7 (23.7.0.25.01)? Thank you. @GeraldVenzl
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@OracleSK
Stefan Koehler
1 year
Details about Spectre v2 Mitigations and speculative executions 🤓 https://t.co/PRwKXQ9777
Tweet card summary image
blogs.oracle.com
A one stop shop for learning all about Speectre v2 mitigations on x86 architecture.
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@chris_skyflier
Christoph Lutz
1 year
For geeks: two bpftrace scripts to map UTS event and component names to their internal ids. https://t.co/cZxjMdItbY https://t.co/CCDmu6kDGC Didn’t plan on it, but sometimes the rabbit hole chooses you... Turns out "oradebug doc" doesn't expose all trace events.
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@TanelPoder
Tanel Poder 🇺🇦
1 year
Profile Explorer is a tool for viewing CPU profiling traces collected through the Event Tracing for Windows (ETW) infrastructure on machines with x64 and ARM64 CPUs https://t.co/MREFbyZlHL
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@chris_skyflier
Christoph Lutz
1 year
It continues to amaze me time and again what bpf based tracing makes possible … been looking into Oracle write consistency and update restart mechanics recently and tinkered with a bpftrace script to detect restarts system-wide and in real-time: https://t.co/OSi1Pub9C5 🤓
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@chris_skyflier
Christoph Lutz
1 year
1/4 Interesting UPDATE restart variation: Oracle may try to update a row during the ALL LOCKED phase that wasn't returned and locked in the prior LOCK phase (row 0 in the example).
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@OracleSK
Stefan Koehler
1 year
A visionary leader for a nation, and look at what we got: @Bundeskanzler with his „Sparbuch“ and „debt fantasies“ 🫣
@nayibbukele
Nayib Bukele
1 year
I told you so.
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@OracleSK
Stefan Koehler
1 year
Ahh I found it. After struggling with all the login errors you have a tiny little link called "Or sign in to other Oracle Support portals" (Support for Oracle Hardware, Software, and Managed Cloud) on the landing page. There you have the good old important information.
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@OracleSK
Stefan Koehler
1 year
What is this new My Oracle (Cloud) Support Portal? At first I only got errors when accepting the Terms of Use and now the bug database is gone? How can I search the bug database in the new my Oracle (Cloud) Support Portal? All I see is "Knowledge", "Documentation" & Communities
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@OracleSK
Stefan Koehler
1 year
Since a few hours I am going down the CPU scaling governors/drivers rabbit hole - Oh boy this is a mess 😱 Love the term "Autonomous frequency scaling" with Intel CPUs and we all know what this means 😅 Can't set fixed perf mode with active intel_pstate https://t.co/NJPoVt1EcI
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@OracleSK
Stefan Koehler
2 years
Hey sweetie - Ghidra with XCOFF loader/support https://t.co/JRuLufsG2y It was a little bit messy to get it compiled and running with Ghidra on Kali 2024.3 but we can finally start digging
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@OracleSK
Stefan Koehler
2 years
I know that there is some sample code here ( https://t.co/S4xQi8Fbd0 ) but that would be a huge step backward if I need to code my own agent for reading data from TEQ and putting into MQ or vice versa.
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@OracleSK
Stefan Koehler
2 years
Shout out to my Oracle folks The Oracle Messaging Gateway is deprecated according to the Oracle 23ai documentation and TxEventQ is the new way to go. Ok fine, but how to integrate MQ Series with TxEventQ now. Do we need to code our own client/agent for that? 🤔 Thank you 🙏
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@TanelPoder
Tanel Poder 🇺🇦
2 years
I will be speaking at the @ebpfsummit 2024 conference about a new way for approaching Linux system performance, with https://t.co/ReMaZ0MbtG and eBPF! Free online event on September 11th, 2024 https://t.co/OoeQoLhSn9 See you there!
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@OracleSK
Stefan Koehler
2 years
Let‘s go Jerome 🚀 Brrrrrrrrrrrrrrrrrr #BTC
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