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…
GoldenGate: Initial Load DB2 to Oracle and HANDLECOLLSIONS
In this blog post I mainly want to discuss the GoldenGate parameter HANDLECOLLISIONS and do some tests to find out about its reliability. I always felt very uncomfortable whenever I needed to use it. So this post is also about the desire for trust in…
Important behaviour change between bash version 4.3 and 4.4
Please be aware about important behaviour change between bash version 4.3 and 4.4. You can observe it for example while migrating from Oracle Linux 7 to 8/CentOS 7 to Rocky Linux 8/etc. as version 7 of RHEL compatible system comes with bash 4.2, whereas version…
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…
Finding Wrong Hints
Introduction I use the Oracle Database since many years. And I use hints. For experiments, but also in production code. There are cases when you know more than the Oracle Database. For example about the cardinality of a data source or the number of result…
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…
GraalVM Native Image – First Impressions
Introduction A native image is an operating system specific executable file. You can build such an image for basically every application running on a Java virtual machine. This approach promises faster start-up times and lower resource consumptions. This makes it appealing for serverless computing, auto-scaling…
Oracle ACE
After less than 2 years after becoming Oracle ACE Associate, I’m happy to share that I have been promoted to Oracle ACE! I have recently changed my focus from Oracle Database to MySQL, but as it is currently owned by Oracle, I hope I will…
Do Not Format Invalid Code in SQL Developer
Introduction What happens when you call the formatter in SQL Developer for invalid code? Until recently SQL Developer tried to format it anyway. This produced strange results in some cases. Starting with SQL Developer version 21.2.0 there is a hidden option to suppress formatting when…
Lightweight Formatter for PL/SQL & SQL
TL;DR Bye bye heavyweight formatter. Long live the lightweight formatter. Are you using Oracle’s SQL Developer or SQLcl? Then install these settings and press Ctrl-F7 to produce code that conforms to the Trivadis PL/SQL & SQL Coding Style. A compromise between conformity and individuality. Heavyweight…