I’m a lazy programmer! That was one important detail I learned from Roelant Vos in his training last week. But there were many other interesting topics. A personal summary of a 3-days class about Data Warehouse Design Patterns.
Category Archives: Data Vault Modeling
Data Vault Queries and Join Elimination
If you work with Data Vault for a data warehouse running in an Oracle database, I strongly recommend to use Oracle 12.2 or higher. Why that? Since Oracle 12c Release 2, join elimination works for more than one join column. This is essential for queries on a Data Vault schema.
Oracle 19c: Auto-List Partitioning HIGH_VALUE Bugs fixed
New features are one reason to upgrade to a new Oracle release, bug fixes of known bugs are another one. With Oracle 19c, at least two bugs related to Automatic List Partitioning were fixed. I did some tests with Auto-List Partitioning on an Oracle 19.3 database.
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.
My Sessions at DOAG 2017
This year, I had the opportunity to present three sessions at the DOAG conference in Nuremberg – one on each conference day. Here a short summary of the sessions and links to the downloads.
Oracle Database In-Memory and Hash Keys
Hash keys are often used as primary keys in Data Vault environments. When loading dimensional data marts from a Data Vault schema, it seems to be obvious to use them as dimension keys, too. At least in combination with Oracle Database In-Memory, this is not a good idea.
An Intensive Week in Colorado
In the last couple of days, I joined several interesting events in Colorado. First, I was able to take part of the “Advanced Data Vault & Ensemble Modeling Summit” at Genesee Academy. After that, I attended the first “Global Data Summit” conference in Golden, Colorado. And finally, I was invited to a very special dinner of the “Boulder Business Intelligence Brain Trust”.
How to Build Hash Keys in Oracle
Hash keys can be used instead of sequence numbers to build surrogate keys in a Data Warehouse. This is often done in Data Vault environments, and there are some good reasons to do that. But there are also several issues and restrictions with hash keys. So, use hash keys only if you have good reasons for them. And if you decide to use hash keys in your Oracle Data Warehouse, make sure that you do it the right way.
biGENiUS Generates Data Vault
A good idea when working with Data Vault is to generate the tables and load processes to avoid a lot of manual development. biGENiUS, the Data Warehouse automation tool of Trivadis, is now able to generate Data Vault objects.
Data Vault Book Recommendations
Data Vault is getting more and more popular for modeling Data Warehouses. Some of my colleagues asked me for book recommendations about this modeling method. Here a short review (from my personal point of view) of two Data Vault standard books.