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DOAG 2021 gems: DBMS_XPLAN.COMPARE_PLANS
The most excellent #DOAG2021 conference ended last week. I have attended quite a few presentations and took lots of notes. I particularly enjoyed Conner McDonald‘s presentation about 25 years of tips and techniques. One of these tips prompted this blog post ;) Turns out I have only seen a change to DBMS_XPLAN in passing. Its…
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Configuring a VM using Ansible via the OCI Bastion Service
In my previous post I wrote about the creation of a Bastion Service using Terraform. As I’m incredibly lazy I prefer to configure the system pointed at by my Bastion Session with a configuration management tool. If you followed my blog for a bit you might suspect that I’ll use Ansible for that purpose. Of…
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Create an OCI bastion service via Terraform
Maintaining bastion hosts (a “jump box” or other network entry point directly exposed to the Internet) is somewhat frowned upon by security conscious architects, for good reasons. In my opinion the only way to connect on-premises systems to the cloud is by means of a dedicated, low-latency/high-bandwidth, and most importantly well-secured link. I never liked…
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The performance story that didn’t turn out as one: a case of or-expansion and how the database mitigated the problem on its own
Recently I had a bit of time to study the effect of an optimizer query transformation, the so-called or-expansion in Oracle 19c. I thought there might be performance implications with statements using bind variables transformed in this way. My limited testing suggests that isn’t necessarily the case as the optimiser is remarkably resilient. Still I…
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Deploying I/O intensive workloads in the cloud: Oracle Automatic Storage Management (ASM)
Over the past month I wrote a few posts about deploying I/O intensive workloads in the cloud. Using standard Linux tools, mainly Logical Volume Manager (LVM) I tried to prevent certain pitfalls from occurring. Although I’m a great fan of LVM and RAID (and their combination), there are situations where LVM/Software RAID aren’t part the…
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Resolving slight niggles of Enterprise Manager Express 19c
This page, should I remember I wrote it, hopefully addresses the slight niggles I have with Oracle Enterprise Manager Express. I always forget how to solve these and it takes me a minute to remember. I hope this page helps me jump start my memory. If you have any additional niggles to report please do…
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Deploying I/O intensive workloads in the cloud: mdadm (aka Software) RAID
The final part of my “avoiding pitfalls with Linux Logical Volume Manager” (LVM) series considers software RAID on Oracle Linux 8 as the basis for your LVM’s Physical Volume (PV). It’s still the very same VM.Standard.E4.Flex running Oracle 19.12.0 on top of Oracle Linux 8.4 with UEK6 (5.4.17-2102.203.6.el8uek.x86_64) I used for creating the earlier posts.…
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Building a Debian 11 Vagrant Box using Packer and Ansible
Sometimes it might be necessary to create one’s own Vagrant base box for reasons too numerous to mention here. Let’s assume you want to build a new base box for Debian 11 (bullseye) to run on Virtualbox. Previously I would have run through the installation process followed by customising the VM’s installed packages and installing…
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Install the Oracle Cloud Infrastructure CLI on Ubuntu 20.04 LTS
This is a short post on how to install/configure the Oracle Cloud Infrastructure (OCI) Command Line Interface (CLI) on Ubuntu 20.04 LTS. UPDATE 220221: Ubuntu 20.04 LTS is going out of support very soon – you should really use a different LTS release instead of this one! The steps presented in this article should apply…
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Deploying I/O intensive workloads in the cloud: LVM RAID
I recently blogged about a potential pitfall when deploying the Oracle database on LVM (Logical Volume Manager) with its default allocation policy. I promised a few more posts detailing how to potentially mitigate the effect of linear allocation in LVM. The post was written with the same Oracle 19.12.0 database deployed to Oracle Linux 8.4…
