Learning, relearning or unforgetting…

What value is there in a DISABLEd constraint?

This was a question on the OTN forums this week and a) my first reply was wrong and b) I couldn’t find a clear demonstration elsewhere.

The documentation is clear.

RELY Constraints

The ETL process commonly verifies that certain constraints are true. For example, it can validate all of the foreign keys in the data coming into the fact table. This means that (more...)

DBMS_SCHEDULER jobs running an hour late – DST/BST issues!

This week one of our developers highlighted the fact that the DBMS_SCHEDULER on one of our databases was running jobs an hour later than scheduled until just recently, when the clocks went back (26/10/2014) for British Summer Time (BST) …and now they’re running on-time again! I’d not seen this before, and at first I thought we


Patching Time

Just a quick note to point out that the October PSU was just released. The database has a few more vulnerabilities than usual (31), but they are mostly related to Java and the high CVSS score of 9 only applies to people running Oracle on windows. (On other operating systems, the highest score is 6.5.)

I did happen to glance at the announcement on the security blog, and I thought this short (more...)

Installing Oracle on Windows 64bit

The following steps are what I did for installing on Windows.

1. Download the Oracle installation ZIP files from the Oracle Downloads page.

DB Install 15

2. Unzip the two 12c downloads files into the same directory.

3. Go to the newly created directory (it is probably called 'database') and you will find a file called setup.exe. Double click on this file.

DB Install 1

After a couple of seconds you will see the Oracle Database (more...)

Découverte : Workshop Enterprise Manager

Oracle France propose début octobre un workshop permettant de découvrir; à travers 6 ateliers de manipulation,  la solution Oracle Enterprise Manager 12c Cloud Control.

Annonce : MySQL & Enterprise Manager

Oracle a annoncé l'extension des capacités d'Oracle Enterprise Manager à superviser des bases de données MySQL.

Plus d'informations :

Complément : Sauvegarder une instance dans le Cloud Publid Oracle

Depuis avril 2014, Oracle propose une solution de sauvegarde Cloud, appelée Oracle Database Backup Service : 

La console Oracle Enterprise Manager 12c vous permet de piloter vos sauvegardes et restaurations directement sur Oracle Database Backup Service.

Plus d'informations :

Complément : Analyse des performances sur du long terme

Complément: Mettre en place AWR Warehouse

Le patch permettant la mise en place d'AWR Warehouse dans Enterprise Manager est disponible ( cf note 1907335.1) !

Pour activer AWR Warehouse, l'administrateur d'Enterprise Manager doit :
  • Créer une instance de base de données Oracle Database (recommandé) ou pour le référentiel AWR
  • Découvrir l'instance dans EM12c
  • Appliquer le patch sur l'OMS (cela permet d'avoir AWR Warehouse dans le menu)
  • Appliquer le (more...)

Move That Datafile!

Moving datafiles has always been a pain.  There are several steps, it’s fairly easy to make a mistake and it requires the datafile to be offline.  There are also different steps depending on whether the database is in ARCHIVELOG mode or not.  In ARCHIVELOG mode, the steps are…

1)      Take the tablespace containing the datafile offline
2)      Copy/rename the datafile at the OS layer

Oracle 12c – New SYS-level Administration Privileges

For a while now, Oracle has been moving its security model toward a more differentiated set of privileges than just SYSDBA and SYSOPER.  We saw this in 11g with the SYSASM privilege.  This is in response to the growing number of DBA shops that delineate permissions at a more granular level, even among DBAs.  Rather than saying, “Here’s my DBA team, everyone has SYSDBA,” more and more IT shops are defining DBA (more...)

My MySQL database impressions

I have been in the data and database world for over a decade now, working with mainly Oracle and data integration projects with Salesforce.

I have also spent time working with MySQL a relational database with open source roots, now part of Oracle. In this post I want to talk about my impressions of MySQL and some tips and tricks I learned working with it.

First and for all, you will have to be ready (more...)

The OLAP Extension is now available in SQL Developer 4.0

Oracle Database 11gR2 ( installation on Oracle Linux 6.4

In this post, I’m installing the Oracle Database 11g Release 2 ( software on Oracle Linux 6.4, along with optional instructions on how to apply the latest Patch Set Update (PSU) to your new Oracle home. First and foremost, before you start, make sure your Linux server meets the minimum hardware requirements: 1GB of RAM (plus


OSD-04400: unable to acquire internal semaphore for process and OS 183 (Windows)

I hit the following problem with a database running on Windows 2003 this morning (info pulled from the alert log).  The database had failed to restart after a client’s cold backup process ALTER DATABASE MOUNT Wed Jan 15 22:32:08 2014 ORA-09341: scumnt: unable to mount database OSD-04400: unable to acquire internal semaphore for process


Exadata Storage Server Version Released

Oracle has released the much-anticipated version of cellsrv compatible with Oracle Database (patch #16980054). Before thinking about upgrading, read MOS note #1571789.1 carefully.  Unless you are planning to run database 12c on your Exadata, it would be advisable to continue down the 11.2 branch (more...)

Oracle Announces Exadata X4-2

Today, Oracle announced the Exadata X4-2 model.  The X4 has some considerable improvements, namely:

  • 12-core Intel Xeon e5-2697 CPUs, up from the 8-core models found in the X3-2 (hello, database licenses!)
  • 256GB RAM per database server, upgradeable to 512GB
  • 96GB RAM per storage server
  • 800GB Sun Flash F80 cards (more...)

OSP #2c: Build a Standard Platform from the Bottom-Up

This is the fourth of twelve articles in a series called Operationally Scalable Practices. The first article gives an introduction and the second article contains a general overview. In short, this series suggests a comprehensive and cogent blueprint to best position organizations and DBAs for growth.

This article – building (more...)

Oracle Database 12c PRAGMA UDF and WITH clause enhancements

Here are two interesting enhancements in Oracle database 12c PL/SQL. PL/SQL subprogram defined using WITH clause of a subquery – Oracle database 12c allows PL/SQL declaration section in the WITH clause. One can define PL/SQL function or procedure into a WITH clause. Functions declared in the PL/SQL declaration section can (more...)

Stuck Timezone Upgrades and Smart Scans

I heard a strange report from a client late last week - they weren't getting any smart scans on their Exadata - a data warehouse, no less (and we checked to see if cell_offload_processing was set to true).  Queries would run normally, but for some reason, the "cell physical IO (more...)