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Database Administration & Monitoring

Daniel Westermann

Getting started with Citus – Setting up a four node cluster

By | AWS, Database Administration & Monitoring | No Comments

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. pgpool-II). But even if you have something in place, you need to deal with replications…

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Steven Naudet

Virtual Symposium SQL Server & Azure SQL – Session: Debugging without debugger

By | Database Administration & Monitoring, SQL Server | No Comments

As a consultant at dbi services we can dedicate a significant part of our time to training and I took the opportunity today to attend an online conference. In this blog post, I will present this event and one of the sessions that particularly interested me. The event I followed is the Virtual Symposium – SQL Server & Azure SQL organized by SQLServerGeeks. It’s a free event that can easily be followed on Zoom but…

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Karsten Lenz

CentOS 8 binary compatible alternatives

By | Database Administration & Monitoring | No Comments

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 of May 2029 to 31st of December 2021 brings many people in trouble which has…

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Mouhamadou Diaw

Patching ODA HA from 19.8 to 19.10

By | Database Administration & Monitoring, Database management, Operation systems, Oracle | No Comments

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 / /u01 and /opt filesystems. Below the state of our filesystems [[email protected] Downloads]# df -h /…

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Daniel Westermann

PostgreSQL: set_config and current_setting

By | Database Administration & Monitoring | No Comments

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 file (or setting parameters at the cluster, database and user level). In the posts that…

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Daniel Westermann

Building a PostgreSQL EC2 AMI for testing the latest commits

By | AWS, Database Administration & Monitoring | No Comments

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 can easily deploy new VMs, do your tests and get rid of it afterwards with…

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Jérôme Dubar

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

By | Database Administration & Monitoring, Database management, Oracle | No Comments

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 me if services could be used for switching between PDBs without modifying client’s connexion, for…

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Steven Naudet

SQL Server CPU limitation for Express and Standard Edition

By | Database Administration & Monitoring, SQL Server | No Comments

Introduction When performing an audit on an SQL Server VM the first thing the system administrator told me was that there’s no issue with the CPU on this box, the monitoring shows it’s always around 50% usage. Problem Here is the Task Manager: The average CPU usage on this VM is indeed 50% but half of the cores are stuck at 100%. There are two SQL Server instances installed on this server but they are…

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Steven Naudet

SQL Server: Get email notifications for Error Log entries

By | Database Administration & Monitoring, SQL Server | No Comments

Introduction In a previous blog post, I did a T-SQL script reading Audit files to send emails with valuable information about instance changes. In this one, you will see how to get nice emails from critical errors or specific events occurring on the instance using the ErrorLog. A common best practice for any DBA is to configure SQL Server Agent Alert for errors with severity 17 to 25. Alerts are also often set for less…

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Steven Naudet

SQL Server: How to delete the msdb backup history kindly

By | Database Administration & Monitoring, SQL Server | No Comments

This week I noticed some slowness on queries related to backup history. The instance had a huge msdb database (more than 10GB size), the backup history had never been purged. I already wrote a post on this topic and provided a small PowerShell script using dbatools to clean the backup history. The issue with sp_delete_backuphistory or Remove-DbaDbBackupRestoreHistory is that the operation is done as one transaction and this could badly impact the msdb transaction log…

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