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.
The KubeCon around the Kubernetes technology was one of the events I dreamed to attend since I’m focusing on the CloudNative solutions. I had the great opportunity to attend the KubeCon & CloundNativeCon in Amsterdam with my colleague Benoît Entzmann. There is now CNCF-hosted Co-located events adding more topics and interesting sessions. This is community-driven, vendor-neutral events hosted and managed…
Problem description In a recent consulting assignment I got the following task: A server with a specific IP address (Application server or Oracle Client) should be able to connect to a specific DB-user only. E.g. a single application server responsible for reports should be able to only connect to a specific read-only-user in the database. Other application servers should be…
This was a really interesting customer case and I learned a lot by troubleshooting this. The original request was: We have two databases connected via postgres_fdw and when a merge join is chosen by PostgreSQL we get the wrong result. Setting enable_mergejoin to off causes PostgreSQL to go for a hash join and the result is correct. Well, personally, I’ve…
SQL Server 2022 introduced “CE Feedback“, a feature that adjusts some Cardinality Estimation model assumptions at a query level by applying Query Store hints. In this blog post, I’ll use an example query from the CE Feedback documentation to look in more detail at how CE works. The goal is to better understand how SQL Server uses certain assumptions to…
First, a little explanation about TLS, DTLS & SSL: We can find 3 versions of SSL (1.0,2.0 & 3.0) and 4 versions of TLS (1.0,1.1,1.2 & 1.3) actually. Even if some protocols are deprecated or no more used, it’s good to verify. TLS 1.0 is available for Windows Server 2008 and more TLS 1.1& 1.2 is available from Windows Server…
To reduce load on the Primary DB in a Data Guard configuration you may decide to do your rman backups from the Standby site. A very common approach today is to use NFS as the backup location, especially when using platforms like Exadata Cloud at Customer. I recently had a case where both the Primary and the Standby site had…
Prometheus is a popular open-source monitoring system that helps track and alert for various applications. However, regarding security, there are some essential things to consider. Prometheus server, for instance, does not provide authentication or TLS encryption out of the box, meaning anyone accessing the server’s HTTP endpoints can access all of our time-series data. So, what solutions are available?One solution…
Last week some smaller features got committed for PostgreSQL. The first one is an option which can be given to explain for displaying the generic plan for a statement. I’ve written about generic plans in the past, please read this before you continue and are not aware what this is about. Displaying the help for EXPLAIN in psql will already…
Another great PostgreSQL community conference is over, and I came back with a lot of impressions yesterday. It was probably the worst time of the year for the conference to happen, as massive strikes are ongoing in France currently. Nothing the organizers could do here, as this of course was not known when the conference was planned. With some 100+…
I have recently written a blog introducing the Oracle ZDM (Zero Downtime Migration) tool : https://www.dbi-services.com/blog/zero-downtime-migration-zdm-to-oracle-cloud-infrastructure-oci/ I have also done some tests performing an offline logical database migration from a database running on an OCI VM (this would simulate an on-premises database) to an ADB (Autonomous DataBase) using a backup location in OCI. I would like through this blog to…
