20 Years Working for Trivadis

Today, it is exactly twenty years ago since I started my job as a consultant for Trivadis. In 1999, I never thought that I will stay in one company for such a long time. A retrospective of the last two decades.

Materialized View Refresh for Dummies

Materialized Views are often used in data warehouses to improve query performance on aggregated data. But what if it takes too long to refresh the materialized views? Here are some basic rules to improve refresh performance.

Data Types of Join Columns

The data type of primary key and foreign key columns has an impact on the query performance. This should be considered in the design decision of keys in a Data Vault schema.

Star Schema Optimization in Autonomous Data Warehouse Cloud

Oracle Autonomous Data Warehouse Cloud does not allow to create indexes. Is this a problem for star schemas because no Star Transformation can be used? Or are the required bitmap indexes automatically created? A look under the hood of ADWC.

10 Tips to Improve ETL Performance – Revised for ADWC

The Autonomous Data Warehouse Cloud (ADWC) is a self-configuring, fast, secure and scalable platform for data warehouses. Does this mean we don’t have to take care anymore about performance of our ETL processes? Which performance tips are still important for us, and where can we hand over the responsibility to ADWC? A revised version of an old blog post, with regard to Oracle’s Data Warehouse Cloud solution.

Gathering Statistics in the Autonomous Data Warehouse Cloud

Optimizer statistics are essential for good execution plans and fast performance of the SQL queries. Of course, this is also the case in the Autonomous Data Warehouse Cloud. But the handling of gathering statistics is slightly different from what we know from other Oracle databases.

External Tables in Autonomous Data Warehouse Cloud

In Oracle Autonomous Data Warehouse Cloud, External Tables can be used to read files from the cloud-based Object Storage. But take care to do it the official way, otherwise you will see a surprise, but no data.