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Database

Everything our consultants learn while running databases for customers: Oracle, PostgreSQL, SQL Server, MySQL, MariaDB, MongoDB and Delphix. Expect hands-on posts about installation, day-to-day administration, backup and recovery, performance tuning, replication and upgrades.

PostgreSQL on AWS Graviton2: CFLAGS

By Franck Pachot . In a previous post I’ve compiled PostgreSQL with GCC 7 and GCC 11 with the default options and checked that the ARM v8.2 features were used. However it may not be so simple: PostgreSQL ./configure defines gcc flags to produce a binary that is compatible with older versions of ARM. This means that it may not… 

PostgreSQL, pg_ctl and signals

I believe most people use pg_ctl nowadays to start, stop, or restart a PostgreSQL instance. You can do all these tasks without using pg_ctl, but you’ll notice in a minute that pg_ctl really is your friend. Even if you’re using pg_ctl already, is is good to know what happens in the background and this is the scope of this post.… 

Does it still make sense to deploy a virtualized HA ODA in 2021?

Introduction Starting from version 19.11 of the Oracle Database Appliance software bundle, OLVM will definitely replace OVM server as virtualization engine. This change has quite a big impact as there will be no more virtualized specific deployment. Bare metal will come as a standard for all ODAs, and creating VMs for applications, or even databases, will be possible on top… 

El Carro: The Oracle Operator for Kubernetes

By Franck Pachot . Google Cloud, Open Source and Oracle Databases… what seems to be a paradox is possible, thanks to cloud providers who contribute to open infrastructure. The idea is to use Operators (custom resource controllers on Kubernetes) to automate the Oracle Database operations in a standard, open and portable way. If you ever attempted to run Oracle Database… 

Getting started with Citus – Setting up a four node cluster

One issue with traditional database systems like PostgreSQL is, that you cannot easily scale vertically. Of course you could add read replicas and offload read operations, but that either requires changes in the application, or putting something in front that understands the PostgreSQL dialect and automatically routes writes to the primary and spreads reads across one or more replicas (e.g.… 

CentOS 8 binary compatible alternatives

There is a lot of roumors around since it was anounced to switch CentOS 8 from a Downstream Build from RHEL 8 to a Upstream Build for RHEL 8 on December 8th 2020. Many people asked why a second Upstream to Fedora and the way of communication choosen was sub optimal in diplomatic words. Cutting the support date from 31st… 

Delphix and upgrading the clones (Oracle)

By Franck Pachot . Delphix is a tool for easy cloning of databases. The idea is that all is automated: the user can create a clone, rewind or refresh it with one click. However, I was suprised that the following common scenario is not managed by the Delphix engine: You clone from production, say Oracle 12c You upgrade the clone,… 

Patching ODA HA from 19.8 to 19.10

In this blog I am describing the steps to patch an ODA HA from the version 19.8 to version 19.10. The patching was done with a customer. Thanks to Pierre. The name of the servers were changed The ODA is an X8-HA with following nodes -server-aa -server-ab Before starting the patches, be sure that you have enough space on /… 

PostgreSQL: set_config and current_setting

PostgreSQL comes with a rich set of administrative functions for various use cases. There are functions to control parameters, there are functions for index maintenance, others are for recovery and or backup control and there is much more. In this post we’ll look at how you can use the build-in functions to set and get parameters without touching the configuration… 

Building a PostgreSQL EC2 AMI for testing the latest commits

Testing the latest features or bug fixes in PostgreSQL can easily be done by pulling the latest commits from the git repository and compile PostgreSQL from source code. I am doing that frequently on my local sandbox VM but this becomes limited when I need more CPUs or more memory. This is where the public cloud really shines, as you… 

Is it possible to switch a service between 2 pluggable databases?

Introduction In an Oracle database, services have multiple purposes: identifying group of users prior authenticating them enabling/disabling access to a database for particular groups managing preferred nodes on a RAC configuration redirecting users to the primary after a switchover/failover when using Data Guard or Dbvisit Standby redirecting read only connections to Standby database with Active Guard option A customer asked…