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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.

temBoard on SLES15 – 1 – The WebUI

During our last SwissPUG online meeting there was a presentation about monitoring PostgreSQL with temBoard. A question that came up afterwards was: How to install that on SLES 15 as there are only packages for Debian and CentOS/RHEL. As temBoard is written in Python you can also install it using pip. That requires a bit more work compared to the… 

Clone a Terabyte Database in Seconds

Introduction Have you ever cloned a database using RMAN? Have you ever gotten the advice not to clone during daytime to avoid performance downgrade on the entire storage or network? For a proof of concept, we wanted to evaluate a Pure Storage array in terms of feasibility and speed of database cloning by using storage-based snapshot technology. First, I want… 

Some Artificial Intuition in Oracle SQL_ID?

By Franck Pachot . This post is something I discovered by chance when writing about tagging SQL statement with recognizable comments. We know that Oracle is introducing more and more artificial intelligence and machine learning in the database engine, but here is the first time I see something where random or hash values seems to bring some meaning. There are… 

SQL Server: Create a Shared Storage for your Failover Cluster LAB

I’m currently working on the migration of a Failover Clustered SSAS instance from Windows Server 2012 to Windows Server 2019. The context is quite complex and in order to choose the right migration scenario I need to play with it on my LAB environment first. I usually work with AlwaysOn architectures and it’s not often that I need to set… 

Oracle Java Virtual Machine included in Oracle Database license ?

Introduction A customer of mine asked me a licensing question regarding the usage or Oracle Java (OJVM) in an Oracle database.  Basically this customer have an Oracle Database Standard Edition License and would like to use Oracle JVM in order to load Java classes in his PL/SQL code executed by this database. The customer would like to ensure that his… 

Should CPU-intensive logic be done in the DB or in application server?

By Franck Pachot . Should CPU-intensive logic be done in the DB or in application server? Here was a answer found in Reddit: Comment byu/CacheMeUp from discussion inPostgreSQL Reducing the CPU usage on the database server is a major cost saver with commercial databases, like Oracle Enterprise Edition where you pay license per core. But even in Open Source, on-premises… 

Oracle Data Integrator Cloud

Data and applications integration is always a technical challenge for most of the companies. All data integration tool ensures that information is timely, accurate, and consistent across complex systems. Oracle Data Integrator (ODI) is different than traditional data integration tools in the sense it integrates data in a different orders. ODI is known as en E-LT because it Extracts data… 

ORA-32635: not a single cell reference predicate

By Franck Pachot . I spent 30 minutes to try to understand this error with a query that I’ve run in many environments for years. So if you google it you may arrive here and the solution may be checking whether you have NLS_COMP=LINGUISTIC SQL> alter session set nls_comp=linguistic; Session altered. SQL> alter session set nls_language=french; Session modifiee. SQL> select… 

Adding nmon to Oracle OSWatcher

nmon (nmon is short for Nigel’s performance Monitor for Linux on POWER, x86, x86_64, Mainframe & now ARM (Raspberry Pi)) is a nice tool to monitor a Linux system. Originally it came from the AIX-platform, where it is very popular. I asked myself if I can add nmon to the OSWatcher framework to automatically gather nmon data. It is actually… 

PostgreSQL 14: LZ4 compression for TOAST

In PostgreSQL a row or tuple can not span multiple pages (a page is typically 8kB), but of course you can store larger rows and PostgreSQL brakes and compresses these rows into smaller chunks by using a technique called TOAST. Once your table contains a toast-able data type a so-called toast table is created automatically. Up to PostgreSQL 13 you… 

Copy or Migrate a SSISDB environment 2.0

Based on the blog “Copy or Migrate a SSISDB environment” of my colleague Christophe, I create a new one named 2.0. In the precedent script, you need to give the folder name and environment name and he generates all environment variables for these 2 parameters. In my case, I need to generate all folders and what are in these folders.… 

Foreign Keys in MySQL, SQL, NoSQL, NewSQL

By Franck Pachot . In the NoSQL times, it was common to hear thinks like “SQL is bad”, “joins are bad”, “foreign keys are bad”. Just because people didn’t know how to use them, or they were running on a database system with a poor implementation of it. MySQL was very popular because easy to install, but lacking on many…