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.
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.
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.
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? In this blog post, I will write about multi-version loads into a satellite table.
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.
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 year.
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 demo script for my DOAG presentation about SQL features in Oracle 20c. Unfortunately, it turned out differently than planned. A drama in four acts.
When was the last time you looked into the Oracle documentation? If you rarely or never do so because you think you know the Oracle database, take another look at docs.oracle.com and browse in the online documentation. It’s worth it!
I work with SQL since decades, and I think to have some practical experience with writing SQL queries on Oracle databases. So why should I buy a book about practical Oracle SQL? If you are in a similar situation like me, read this book review.
Although Query Rewrite on Materialized Views is a powerful feature which is available in Oracle databases for a long time, it is rarely used. Many developers and database administrators don’t know about it or do not use it because they think it is too complex. In this blog post, I try to reduce the concerns about complexity with some general design tips for Query Rewrite.
Data Warehousing with Oracle 