Dwh on FromDual GmbH

We build a data warehouse from the General Query Log

oli.sennhauser@fromdual.com (Oli Sennhauser) — Wed, 31 Jan 2024 16:41:13 +0100

The design of a data warehouse differs from relational design. Data warehouses are often designed according to the concept of the star schema.

Data Warehouse Design

oli.sennhauser@fromdual.com (Oli Sennhauser) — Wed, 16 Jun 2021 23:02:43 +0200

This is my cheat sheet for dimensional modelling design techniques of a data warehouse (DWH) according to Kimball/Ross.

Query performance comparison between MariaDB ColumnStore and other Storage Engines

oli.sennhauser@fromdual.com (Oli Sennhauser) — Thu, 03 Jun 2021 15:53:51 +0200

Storage Engines like InnoDB, Aria and MyISAM are Row Stores. They store rows one after the other in blocks or even directly in a single file (MyISAM). On the other hand a Column Store like MariaDB ColumnStore stores all the same attributes (columns) of the rows together in chunks.

Create a single-node MariaDB ColumnStore test installation

oli.sennhauser@fromdual.com (Oli Sennhauser) — Wed, 19 May 2021 19:37:50 +0200

For a long time I wanted to investigate a bit more into the MariaDB ColumnStore architecture. Now I took the time to start with.

Do not trust other peoples benchmarks!

oli.sennhauser@fromdual.com (Oli Sennhauser) — Tue, 06 Apr 2021 13:26:06 +0200

Because they do NOT reflect your problems.

One of our customers upgraded last month from MariaDB 10.2 to MariaDB 10.5. In the same change he also converted all his data warehouse (DWH)/BI tables from MyISAM to Aria. An all this, naturally, without testing. And it miserably failed! And then we were under heavy time pressure to make things working again…

The battle against Oracle is probably over but has the real war begun yet?

oli.sennhauser@fromdual.com (Oli Sennhauser) — Wed, 20 Jan 2010 09:36:00 +0100

According to different sources from the web the decision about the Oracle - Sun merger has been approved by the European commission soon. So at least in the West it is clear what is going on. Let us see what the East decides… [ 1 ], [ 2 ].