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.
By Franck Pachot . Oracle has announced a big feature that should come in the next 12c patch set: the In-Memory option. It will soon be in beta version, so nothing will be published about it until it comes to production. Before that phase, I’m going to explain what we can expect from that feature, besides the ‘In-Memory’,’columnar storage’, and…
Microsoft will introduce four new security permissions in SQL Server 2014. One of them called SELECT ALL USERS SECURABLES is the subject of this post. As explained by Microsoft SQL Server 2014 will allow a database administrator to manage data without seeing sensitive data or personally identifiable information. We can achieve a greater compliance but we must take care what…
By Franck Pachot . Disclaimer: I’ll talk about an undocumented feature that appeared in Oracle 12c – undocumented except if you consider that being exposed in DBA_SEQUENCES as the PARTITION_COUNT is a kind of documentation. So, as the syntax is not documented (I got it only by guessing), you should not use it in production: there are probably some reasons…
By Franck Pachot . Je viens d’assister au Webinar Zero Downtime Migration pour Oracle, présenté par Chris Lawless qui est récemment passé de Product Manager Golden Gate à Product Manager Dbvisit. Je vais détailler ici un point très important évoqué par Chris Lawless. La migration par réplication n’est pas seulement envisagée pour éviter un arrêt de service. Arrêt nécéssaire lors…
By Franck Pachot . sqlplus / as sysdba oradebug setmypid oradebug unlimit oradebug hanganalyze 3 oradebug dump ashdumpseconds 30 oradebug dump systemstate 266 oradebug tracefile_name Your Oracle database – production DB, of course – is hanging. All users are blocked. You quickly check the obvious suspects (archivelog destination full, system swapping, etc.) but it’s something else. Even you, the Oracle…
In-Memory OLTP is one of the best new functionalities of SQL Server 2014 as it was the case with AlwaysOn and SQL Server 2012. In-Memory OLTP is fully integrated with AlwaysOn and also with AlwaysOn Availability Group. During my test with AlwaysOn Availability Group under SQL Server 2014 CTP2, I discovered that a Readable Secondary Replica was not able to…
I was surprised that you have to rebuild indexes that are stored In Memory. My previous posting “SQL Server 2014 – New Features: xVelocity memory optimized columnstore index” explains all processes connected with columnstore indexes. In this article, I will explain why, when, and how to rebuild them. Why do we need to rebuild the Clustered Columnstore Indexes? When a…
By Franck Pachot . Do you use ARCHIVELOG DELETION POLICY TO APPLIED ON ALL STANDBY for your Oracle databases in Data Guard? Maybe you also use the Fast Recovery Area as archive log destination. That’s good practice! But did you ever check that it works as expected? What I mean is this: The archived logs that you don’t need are…
The concept of Multitenant databases, which was introduced with Oracle 12c in June 2013, allows to run several databases on a single instance. Oracle presents this feature as a good solution for Oracle patching. The reason behind it is that it is now possible to unplug a container database (called PDB) from its original container (called CDB), in order to…
By Franck Pachot . Because people know that I really like Oracle AWR reports, they send them to me from time to time. Here is one I have received for Christmas with the following question: ‘Since our AIX server is virtualized, the response times are 4x longer. I feel that we are CPU bound, but cpu usage is mostly idle.…
Oracle DBAAS (Database As a Service) offers a good solution for on demand access to software and infrastructure. In this posting, I will describe the DBAAS implementation with Enterprise Manager Cloud 12c. Why Database as a Service is interesting When a developer team needs a new database, the system administrator has to configure the host, the storage administrator has to…
The choice of the correct character set before you create an Oracle 12c database is an important decision. You have to know the type of data you have to store and the languages needed by the Oracle database. Oracle recommends to choose Unicode for its universality and compatibility. It supports all written languages and most of the technical and scientific…
