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Database Administration & Monitoring

Mouhamadou Diaw

Oracle 20c Data Guard : Validating a Fast Start Failover Configuration

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

In Oracle 20c, we can now validate a Fast Start Failover configuration with the new command VALIDATE FAST_START FAILOVER. This command will help identifying issues in the configuration. I tested this new feature. The Fast Start Failover is configured and the observer is running fine as we can see below. DGMGRL> show configuration verbose Configuration – prod20 Protection Mode: MaxPerformance Members: prod20_site1 – Primary database prod20_site2 – (*) Physical standby database (*) Fast-Start Failover target…

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Mouhamadou Diaw

Oracle 20c : The new PREPARE DATABASE FOR DATA GUARD

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

As you may know, Oracle 20c is in the cloud with new features. The one I have tested is the PREPARE DATABASE FOR DATA GUARD. This command configures a database for use as a primary database in a Data Guard broker configuration. Database initialization parameters are set to recommended values. Let’s see what this command will do for us The db_unique_name of the primary database is prod20 and in the Data Guard I will build,…

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Jérôme Dubar

odacli create-database extremely slow on ODA X8-2 with 19.5

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

Introduction ODA X8-2, in the S, M or HA flavour, is the new database appliance from Oracle. But as a brand new product, you can experience troubles due to the lack of maturity. This time, it concerns database creation that can be extremely slow on these servers if you are using ODA 19.5. Deployment, appliance creation and core configuration X8-2 reimaging is fine, and appliance creation is done without any problem on X8-2. Don’t hesitate…

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Saïd Mendi

How can Docker help a MariaDB cluster for Disaster/Recovery

By | Database Administration & Monitoring | No Comments

Mistakes or accidental data deletions can sometimes happen on a productive MariaDB Galera Cluster and this can be disastrous. There are so many cases I have heard by customers and hereafter are some of the most common: – dropping one column of a table – dropping one table – updating a big table without a where clause What if it was possible to restore online a subset of data without downtime?

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Control-M/EM – Update ctmuser & emuser DBO password

By | Control-M, Database Administration & Monitoring, Database management | No Comments

Introduction: For security purposes we sometimes must update the password of our Control M architecture. This task seems to be easy, but you must be careful to update the passwords wherever they are used. Today we will check how to update the password of our Control M infrastructure including application user and database owner for each of our databases.   Prerequisites: Be sure to have the old password to proceed easier.( not mandatory but easier…

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Franck Pachot

How SQL Server MVCC compares to Oracle and PostgreSQL

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

By Franck Pachot . Microsoft SQL Server has implemented MVCC in 2005, which has been proven to be the best approach for transaction isolation (the I in ACID) in OLTP. But are you sure that writers do not block readers with READ_COMMITTED_SNAPSHOT? I’ll show here that some reads are still blocked by locked rows, contrary to the precursors of MVCC like PostgreSQL and Oracle.

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Jérôme Dubar

Should I go for ODA 19.5 or should I wait until 19.6?

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

Introduction As you may know, Oracle Database 19c is available for new (X8-2) or older Oracle Database Appliances since several weeks. Current version is 19.5. But when you go to the official ODA documentation , it still first proposes version 18.7 not compatible with 19c databases. Here is why. 19c database is the final 12.2 First of all, 19c is an important release because it’s the terminal release of the 12.2, as 11.2.0.4 was for…

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