Infrastructure at your Service

All posts by Daniel Westermann

Daniel Westermann
Senior Consultant and Technology Leader Open Infrastructure

Daniel Westermann has more than 10 years of experience in management, engineering and optimization of databases and infrastructures. He is specialized in Oracle Technologies as Performance Optimization and Tuning, Standardization, Backup & Recovery, in High Avaibility solutions as Oracle Real Application Clusters (RAC), Oracle Data Guard, Oracle Grid Infrastructure, as well as in storage technologies as Oracle Automatic Storage Management (ASM). Daniel Westermann is Oracle Certified Professional 10g/11g/12c. He is also a PostgreSQL Plus 9.0 Professional and a Postgres Advanced Server 9.4 Professional. Prior to dbi services, Daniel Westermann was Management System Engineer at LC SYSTEMS-Engineering AG in Basel. Before that, he worked as Oracle Developper & Project Manager at Delta Energy Solutions AG in Basel (today Powel AG). Daniel Westermann holds a diploma in Business Informatics (DHBW, Germany). His branch-related experience mainly covers the pharma industry, the financial sector, energy, lottery, telecommunications.
Daniel Westermann

No journal messages available before the last reboot of your CentOS/RHEL system?

By | Database Administration & Monitoring | No Comments

As you probably noticed RedHat as well as CentOS switched to systemd with version 7 of their operating system release. This also means that instead of looking at /var/log/messages you are supposed to use journcalctl to browse the messages of the operating system. One issue with that is that messages before the last reboot of your system will not be available, which is probably not want you want.  

 
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Daniel Westermann

Are statistics immediately available after creating a table or an index in PostgreSQL?

By | Database Administration & Monitoring | No Comments

While giving the last PostgreSQL DBA Essentials workshop this question came up: When we create a table or an index: are the statistics available automatically? To be more precise: When we create and load a table in one step, create an index on that table afterwards: Do we have the statistics available by default or do we need to wait for autovacuum to kick in or analyze manually? Lets see …  

 
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Daniel Westermann

firewalld rules for Veritas Infoscale 7.3 with Oracle

By | Database Administration & Monitoring | No Comments

You might wonder, but yes, Veritas is still alive and there are customers that use it and are very happy with it. Recently we upgraded a large cluster from Veritas 5/RHEL5 to Veritas InfoScale 7.3/RHEL7 and I must say that the migration was straight forward and very smooth (when I have time I’ll write another post specific to the migration). At a point in time during this project the requirement to enable the firewall on…

 
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Daniel Westermann

Can I do it with PostgreSQL? – 18 – Instead of triggers on views

By | Database Administration & Monitoring | No Comments

It has been quite a while since the last post in this series but today comes the next one. Being at a customer this morning this question popped up: Can we have instead of triggers on a view in PostgreSQL as well? I couln’d immediately answer (although I was quite sure you can) so here is the test. I took an example for Oracle from here and re-wrote it in PostgreSQL syntax.  

 
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Daniel Westermann

Auto pre-warming in EDB Postgres Advanced Server 10

By | Database Administration & Monitoring | No Comments

Some days ago EDB Postgres Advanced Server 10 was released and one feature which might be handy is auto pre-warming. What this does is to save all the buffers (or better a description of the buffers) which are currently loaded in to shared_buffers to disk and then re-read the buffers automatically when the instance is restarted. Lets see how it works.  

 
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Daniel Westermann

Displaying the contents of a PostgreSQL data file with pg_filedump

By | Database Administration & Monitoring | No Comments

Did you ever wonder what exactly is in a PostgreSQL data file? Usually you don’t care, I agree. But there might be situations where knowing how you can do this might be a great help. Maybe your file is corrupted and you want to recover as much data as possible? Maybe you just want to do some research. There is a utility called pg_filedump which makes this pretty easy. Lets go …  

 
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Daniel Westermann

Can I have the same table published and subscribed (bi-directional) in PostgreSQL 10 logical replication?

By | Database Administration & Monitoring | No Comments

When you start using PostgreSQL 10 logical replication you might think it is a good idea to setup bi-directional replication so you end up with two or more masters that are all writable. I will not go into the details of multi master replication here (conflict resolution, …) but will show what happens when you try to do that. Lets go …  

 
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