Our company has been delivering an ERP solution for laundries for more than 25 years. Our application uses Oracle, Java, Spring, and JDBC as its backbone.

Most of the performance problems reported by our customers find their root cause in the persistence layer. During his course, Vlad showed us how we should tackle these kinds of issues, breaking up the execution time of a statement into atomic bits and improving the performance for each of them. We found that optimizing the persistence layer is much more than just writing an SQL query as efficiently as possible. The framework allows for a lot of configuration we were not aware of, even in our case, where we are using plain JDBC. There are also some other architectural decisions that might have an amazing impact on the speed, such as caching, batching, or fetching options.

I enjoyed the fact that Vlad successfully managed to deliver custom training tailored to our needs. He had no problem adjusting the content, as he immediately understood our application’s architecture. Although his course contains a lot of information on various DBMSs, such as SQL Server, PostgreSQL, and MySQL (also comparing their performances) and on frameworks such as Hibernate, he focused on the technologies we are currently using and provided a lot of tips and tricks to help us tune our data access layer. The information was delivered at a pace that could be followed by all participants, and he promptly answered all our questions.

The course was delivered online - given the pandemic situation – and we had a very good interaction, with our colleagues being involved in the discussion through periodical Q&A or hands-on exercises.

Vlad offers a repository with an impressive library of integration tests that illustrate each concept presented throughout the course. Given the level of abstraction they provide and the way they were written, using the latest version of Java, taking gain of the latest additions in the JDK, and abiding by the clean code standards, it would not be an exaggeration to say they provide state of the art in this domain. Every developer writing tests should take a look at them to make sure the application is checked for most hidden vulnerabilities.

I highly recommend the High-Performance SQL and Java Persistence Trainings delivered by Vlad for all companies that want to make sure the data management solution in their application is put to proper use!

As a senior architect for enterprise systems, I was drawn to data persistence. So, for over a decade, I stayed in touch with SQL capabilities. It's funny how, in order to find out how much you don't know, you have to be exposed to more knowledgeable people. For me, after having Vlad in our company to deliver a high-level workshop, my previous feeling of being connected to SQL soon shifted to realizing that I've been only scratching the surface when it comes to SQL.

The feedback from our colleagues was diverse, varying from "the next level of SQL", "great examples with real application use-cases", to "wow, can SQL do that?", and "we should give more time to analyzing SQL queries in our projects since data growth can lead to performance issues".

SQL, as any programming language has evolved, both conceptually and practically. Vlad's training presented all these new SQL standard features in a way that was understandable and applicable for every colleague of ours, regardless of their programming language or the SQL database system they are currently using.