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 William Sescu The DBID is a very important part for Oracle databases. It is an internal, uniquely generated number that differentiates databases. Oracle creates this number automatically as soon as you create the database. During normal operation, it is quite easy to find your DBID. Whenever you start your RMAN session, it displays the DBID. oracle@oel001:/home/oracle/ [OCM121] rman target…
In the last posts of this series we talked about restore points, how you could do things that would require the dual table in Oracle and how you can make use of tablespaces in PostgreSQL. In this post we’ll look at what my colleague Clemens thinks is one of the greatest features in Oracle. Can you do external external tables…
In the last posts of this series we talked about restore points and how you could do things that would require the dual table in Oracle. In this post we’ll look at tablespaces. This is one of the features that is available in PostgreSQL but is totally different from what you know from Oracle. In Oracle you need to create…
In the first post of this series we talked about restore points. Another question that pops up from time to time is how you can do things in PostgreSQL that would require the dual table in Oracle. Lets go … The question is: When do you need the dual table in Oracle? Well, everything time you have nothing to select…
By Franck Pachot . Usually, cursor invalidations do not interrupt the current execution of the cursor. You can even drop a table while a query on it is running and the query may end successfully. However some invalidations will throw internal errors that are catch and the cursor execution restarts transparently. I’ve reproduced one here to show the symptoms: it’s…
I’m pleased to announce that Microsoft gives now the opportunity to choose Linux as a new operating system for SQL Server. To try this new version, you can find in the Cloud Azure a new template in the marketplace. In the search bar, tape “SQL Server vnext” and you’ll find the “SQL Server vNext on Red Hat Enterprise Linux 7.2”.…
When discussing with customers about PostgreSQL we often hear that they can do things in one database that they can not do in PostgreSQL. Most of the times this is not true and you actually can do it in PostgreSQL. Maybe not in exactly the same way but this is not surprising as PostgreSQL does implement features not in exactly…
In this blog post, we will show how to install MongoDB on Windows. Download installer First go to the MongoDB download center https://www.mongodb.com/download-center#community. According to your Windows server version, click on the green buton and download the installer (.msi). In our example, we will use the MongoDB Community version for Windows Server 2008 and later. Important: MongoDB is available exclusively…
By Franck Pachot . Upgrading from 12.1 to 12.2 is easy in Oracle Public Cloud DBaaS because you are in multitenant. Here is how to clone a 12.1 PDB to 12.2 service. I’ve a service HP121 in 12.1.0.2 with one pluggable database PDB1 and a service HP122 in 12.2.0.1 with an empty CDB (only CDB$ROOT and PDB$SEED containers). Export TDE…
By Franck Pachot . Easier than unplug/plug, you can move pluggable databases with remote cloning. It’s the same idea but you don’t have to manage the files yourself: the are shipped through database link. However, this uses the ‘remote file protocol’ and it fails with version mismatch: ORA-17628: Oracle error 17630 returned by remote Oracle server ORA-17630: Mismatch in the…
By Franck Pachot . In the previous post I described how simple it is to unplug a PDB and plug it into a newer version CDB. One goal of dictionary separation in the multitenant architecture is to keep system objects on CDB$ROOT only. Knowing that an upgrade does not touch the application metadata and data, does this make PDB upgrade…
By Franck Pachot . 12.2 is available in the Oracle Public Cloud DBaaS. If you have a 12.1 DBaaS service, there’s no button to upgrade it. I’ll describe all the possible upgrade procedures and the first one, and the most simple, is to create a new DBaaS service in 12.2 and unplug/plug the PDBs to it. Here is my DBaaS…
