Recently a customer called us that there is something wrong after upgrading Oracle Database to 19.15 on RedHat. Apparently The amount of RAM consumed by DBWR and process servers became really impressive – as a proof I got screenshots looking like this: They said that before the migration it never looked like this and asked […]
Remember my post, regarding dumping the SGA to read encrypted blocks? What if I tell you, that you can do the same, while being a KVM host administrator with no credentials to a VM itself? Let’s prepare our secure database in a way I did in article AMM vs security. After enabling Oracle Wallet and […]
So apparently this cloud-thing is here for good. You may even say that it became endemic 😉 With cloud there is one potential problem – the bigger and heavier it is, the more possible is the leak. Cloud after all is just a virtualization in a big scale and if you go to public cloud […]
In my previous post I described a case of "enq: TX – row lock contention" that was actually a network latency problem. More and more those kinds of problems (it seems like history happens all over again) caused my friend (Radosław Kut) and me to write a simple tool to analyze SQL performance from a […]
At Trivadis Performance Days 2018 (awesome event by the way) I promised to deliver ODBV3 with support for ASM – and here it is! 🙂 https://github.com/ora600pl/odbv To use it, you have to have access to a user at ASM level with at least SYSDBA privilege. In the connect string you don’t have to add AS […]
It has been crazy few months – organizing POUG2018 took a lot of energy but it was satisfying as hell! 😀 This weekend I had some time to prepare a new version of ODBV for Trivadis Performance Days 2018 where I’ll be talking about the internals of database block storage. The series of articles about […]
After my last article AMM vs security, Martin Berger wrote to me: well, even without AMM you can do it: write your own process which attaches to the same shm segments – and use its memory mapping (?) My response was that it is also possible with ASMM but AMM makes it extremely easy. And […]
Most of us already know that AMM sucks. But usually, we think about disadvantages of AMM in terms of performance. Let’s see why it sucks in the terms of security 😉 Let’s create an encrypted tablespace for HR.EMPLOYEES and protect HR schema with Database Vault. Contents of sqlnet.ora Now we will use dbca to configure […]
In my last blog post I explained a XOR alghorithm that is used to count Oracle database block checksum. I also wrote, that sometimes you are facing problems, that are unresolvable without a low-level knowledge. This is the story of this kind of situation. The story of misread documentation. The story of haste and hex. […]