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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.

Oracle Database Appliance KVM Virtual Instance on ODA 19.12

By Mouhamadou Diaw KVM virtualization uses a kernel-based virtual machine (KVM) to create a virtualized environment for your Linux applications.In this blog I want to share some tasks I did at a client. The client is using ODA 19.12. The databases are created on the bare metal and for the applications, we decide to create virtual machines. What do I… 

Oracle Database Appliance 19.12 Deployment

By Mouhamadou Diaw In this blog I am describing the deployment of an ODA with the version 19.12 Following patches will be needed -Patch 30403643: Oracle Database Appliance ISO Image -Patch 30403673: Oracle Database Appliance Grid Infrastructure Clone for ODACLI/DCS stack -Patch 33152232: Oracle Database Appliance Server Patch for ODACLI/DCS Stack -Patch 30403662: Oracle Database Appliance Database Clone 19.12.0.0.210720 for… 

How to efficiently add constraints to existing tables in PostgreSQL

Is is not a surprise that applications change over time. New tables get added, columns need to be changed or new ones are required, and sometimes you need to add check constraints or foreign keys to already existing tables which contain data. The issue with adding constraints to tables that already contain data is, that PostgreSQL needs to scan the… 

First contact with OCI’s Autonomous Database

Introduction Benefits of going into the Oracle Cloud (OCI) are clear for most of us: no more datacenter and hardware to manage. But what else? On OCI, you can also decide to get rid of part of the DBA tasks (the less interesting ones, for sure). To create your Oracle database environment, you need to choose among these 3 solutions… 

SELECT FROM DUAL : Oracle Performance And Tuning

The DUAL table is automatically created by Oracle and contains one column (DUMMY) and one row (x value). This table is often used by SQL developer in PL/SQL code (Package, Functions, Trigger) to initialize variables storing technical information such as for example SYSDATE, USER or HOSTNAME. Querying DUAL table is generally faster  as we can see below: SQL> select sysdate… 

From Oracle Standard Auditing to Oracle Unified Auditing

In this post, I will not show you all advantages related to Oracle Unified Auditing. For that, read the oracle documentation. You can also read the blogs written by my colleagues : Oracle 12c Unified Auditing Feature in a multitenant environment Oracle 12c – RMAN and Unified Auditing – Does it really work ? Purging Unified Audit Trail in 12cR2… 

Exadata X9M release

I would like to share some personal thoughts. September 28th 2021, Oracle released the eleventh Exadata data machine called “X9M-2” (2 CPU sockets), X9M-8 (8 sockets) and ZDLRA X9M. Exadata is a computing platform to run Oracle RDBMS, zero data loss recovery appliance (ZDLRA) is a platform to backup Oracle RDBMS and based on Exadata hardware. Combining hard- and software… 

Nutanix Era with oracle databases : Part 5 – Clone an oracle database

Now that we have our ORATEST database provisioned (see Nutanix Era blog part 3), that we could run snapshot and take Log Catch Up (see Nutanix Era Blog part 4), we will now see how we can clone an oracle database. For more information on Nutanix products, I would encourage you to visit Nutanix website. Database Menu Source database and… 

PostgreSQL indexes and operators

Creating a standard B-tree index in PostgreSQL is nothing special and usually we do it without thinking about what happens in the background. For the standard data types like e.g. int or text we do not need to know anything about operators or operator classes. In those cases the standard operator class for the data type is applied and all… 

Some basics about time zones in PostgreSQL

As soon as you have an application which works across time zones you will have to deal with that properly in the database. I’ve seen many applications that didn’t care of that at the beginning, and much work had to be done to change the implementation afterwards. The one and only recommendation is: Do it properly from the beginning and… 

Magic Upgrade to 21c with Replay Upgrade Feature

Last week I did some upgrade tests from 19c to 21c. The plan was to copy a 19c PDB to a CDB 21c using Online Clone and then upgrade it to 21c. I have done this many times for 19c as well and just wanted to verify that it still worked with 21c. Clone PDB to 21c CDB Since it…