Book Review: “Faster: How to Optimize a System” by Cary Millsap
There are many books on performance optimization, but this one differs in a few ways. It is more of an entertaining collection of short stories, but with many educational messages. My travel plans for the Kscope22 conference in June this year were suboptimal: My return…
Housekeeping in Oracle: How to Get Rid of Old Data
Have you ever tried to delete a few million rows from a table with several hundred milllions of rows with a DELETE statement? If yes, then you know that this is a very bad idea. With Oracle Partitioning you can do this more elegant and…
Data Vault versus Database Vault
In the Oracle community, the terms “Data Vault” and “Database Vault” are often confused, although they have nothing to do with each other. A short clarification. Some time ago I had a meeting with the development team and the database administrator of one of my…
Performance Tips: PL/SQL Functions in SQL Queries
PL/SQL functions in SQL statements may cause major performance problems. If it is not possible to avoid these calls, there are several solutions to improve the performance. But not for all situations. In my last blog post, I wrote about the impact of function calls in…
Performance Tips: Function Calls in WHERE Conditions
A typical reason of many performance issues with SQL are function calls in the WHERE condition. They make it difficult for the query optimizer to determine the cardinality. Fortunately, there are several ways to solve this problem. Function calls – or any kind of SQL expressions…
2021: Another Year at Home
I never wrote so few blog posts like in 2021. There are several reasons for this. But there are also good news: I was able to attend at least a few conferences this year. As you can see in my blog, I wrote very few…
Multi-Version Load in Data Vault
One of the advantages of Data Vault are the easy load patterns that can be used to load hubs, links and satellites. They are well documented in several books about Data Vault. But what happens if you want to load multiple versions in one batch?…
Performance Comparison: Snowflake vs Oracle Autonomous Data Warehouse
Which data warehouse cloud platform is faster: Oracle Autonomous Data Warehouse or Snowflake Cloud Data Warehouse? The short answer: it depends. For a more detailed answer, read this blog post. Skiing is not recommended at the moment. Because of the current pandemic situation, it’s better…
2020: A Virtual Year
I just presented my last session this year on Trivadis DevDays 2020. Like most conferences in 2020, it was a virtual event. 13 of 16 conference sessions in the last twelve months I was presenting from home. Time to look back to this very special…
Behind the Scenes: Preparing a Live Demo
One of the extensions in Oracle 20c is the possiblity to use the In-Memory Database option for Partitioned External Tables and Hybrid Partitioned Tables. In my opinion, this opens up many possibilities to perform efficient ad-hoc queries on Data Lakes. That’s why I prepared a…