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Apache Cassandra overview

Apache Cassandra is one of the most popular NoSQL databases http://db-engines.com/en/ranking. It is used by many big companies as Facebook, Netflix and many others. Initially the project was initiated by Facebook. In combination with Google BigTable and Amazon DynamoDB,(…)

Oracle 12c and RMAN switch datafile to copy, is it really so easy?

By William Sescu Oracle incrementally updating backups are used quite often because they are easy to setup and restoring a datafile is very fast. It is very fast because you are not really restoring a datafile, you are switching to(…)

Oracle 12cR2: DDL deferred invalidation

By Franck Pachot . In a previous post I described the new V$SQL views about rolling invalidation. I did the example with dbms_stats which is able to do rolling invalidation since 11g. But more is coming(…)

Running PostgreSQL on ZFS on Linux – Compression

In the last posts in this little series we looked at how to get a ZFS file system up and running on a CentOS 7 host and how snapshots and clones can be used(…)

Oracle 12c and RMAN automatic datafile creation

By William Sescu A lot of new features popped up with RMAN 12c, like  Expansion of Multi-section support, or Simplified cross-platform migration and many many more. However, in this post I would like to highlight a small, but very helpful(…)

Documentum story – HA configuration best practice

We went to a performance issue and some failed failover regarding the content server and the JMS. Thus we asked EMC for recommendations and it seems that the configuration can be slightly different than the official documentation. Here are the(…)

Running PostgreSQL on ZFS on Linux – Fun with snapshots and clones

In the last post we looked at how to get a ZFS file system up and running on a CentOS 7 host and how to enable the auto mount of the ZFS file systems. In this post(…)

Running PostgreSQL on ZFS on Linux

ZFS for Solaris is around for several years now (since 2015). But there is also a project called OpenZFS which makes ZFS available on other operating systems. For Linux the announcement(…)

Connecting your PostgreSQL instance to an Oracle database – Debian version

Some time ago I blogged about attaching your PostgreSQL instance to an Oracle database by using the oracle_fdw foreign data wrapper. This resulted in a comment which is the reason for this post: Doing the same(…)

When an index seek operator is not always your friend

Did you ever consider an index seek as an issue? . Well, let’s talk about a story with one of my customers where the context is pretty simple: a particular query that is out of the range of the application’s(…)