Usually, this blog is 100% pro window functions and advocates using them at any occasion. But like any tool, window functions come at a price and we must carefully evaluate if that's a price we're willing to pay. That price can be a sort operation. And as we all know, sort operations are expensive. They … Continue reading How to Avoid Excessive Sorts in Window Functions
Squeezing Another 10% Speed Increase out of jOOQ using JMC and JMH
In this post, we're going to discuss a couple of recent efforts to squeeze roughly 10% in terms of speed out of jOOQ by iterating on hotspots that were detected using JMC (Java Mission Control) and then validated using JMH (Java Microbenchmark Harness). This post shows how to apply micro optimisations to algorithms where the … Continue reading Squeezing Another 10% Speed Increase out of jOOQ using JMC and JMH
jOOQ Tuesdays: Nicolai Parlog Talks About Java 9
Welcome to the jOOQ Tuesdays series. In this series, we’ll publish an article on the third Tuesday every other month where we interview someone we find exciting in our industry from a jOOQ perspective. This includes people who work with SQL, Java, Open Source, and a variety of other related topics. I'm very excited to … Continue reading jOOQ Tuesdays: Nicolai Parlog Talks About Java 9
Benchmarking JDK String.replace() vs Apache Commons StringUtils.replace()
What's better? Using the JDK's String.replace() or something like Apache Commons Lang's Apache Commons Lang's StringUtils.replace()? In this article, I'll compare the two, first in a profiling session using Java Mission Control (JMC), then in a benchmark using JMH, and we'll see that Java 9 heavily improved things in this area. Profiling using JMC In … Continue reading Benchmarking JDK String.replace() vs Apache Commons StringUtils.replace()
10 Cool SQL Optimisations That do not Depend on the Cost Model
Cost Based Optimisation is the de-facto standard way to optimise SQL queries in most modern databases. It is the reason why it is really really hard to implement a complex, hand-written algorithm in a 3GL (third generation programming language) such as Java that outperforms a dynamically calculated database execution plan, that has been generated from … Continue reading 10 Cool SQL Optimisations That do not Depend on the Cost Model
How to Write Efficient TOP N Queries in SQL
A very common type of SQL query is the TOP-N query, where we need the "TOP N" records ordered by some value, possibly per category. In this blog post, we're going to look into a variety of different aspects to this problem, as well as how to solve them with standard and non-standard SQL. These … Continue reading How to Write Efficient TOP N Queries in SQL
JOIN Elimination: An Essential Optimiser Feature for Advanced SQL Usage
The SQL language has one great advantage over procedural, object oriented, and "ordinary" functional programming languages. The fact that it is truly declarative (i.e. a 4GL / fourth generation programming language) means that a sophisticated optimiser can easily transform one SQL expression into another, equivalent SQL expression, which might be faster to execute. How does … Continue reading JOIN Elimination: An Essential Optimiser Feature for Advanced SQL Usage
jOOQ 3.10 Supports JPA AttributeConverter
One of the cooler hidden features in jOOQ is the JPADatabase, which allows for reverse engineering a pre-existing set of JPA-annotated entities to generate jOOQ code. For instance, you could write these entities here: @Entity public class Actor { @Id @GeneratedValue(strategy = IDENTITY) public Integer actorId; @Column public String firstName; @Column public String lastName; @ManyToMany(fetch … Continue reading jOOQ 3.10 Supports JPA AttributeConverter
Finding all Palindromes Contained in Strings with SQL
SQL is a really cool language. I can write really complex business logic with this logic programming language. I was again thrilled about SQL recently, at a customer site: https://twitter.com/lukaseder/status/899626552597590016 But whenever I tweet something like the above, the inevitable happened. I was nerd sniped. Oleg Šelajev from ZeroTurnaround challenged me to prove that SQL … Continue reading Finding all Palindromes Contained in Strings with SQL
jOOQ Tuesdays: Oliver Gierke Talks About Spring Data
Welcome to the jOOQ Tuesdays series. In this series, we’ll publish an article on the third Tuesday every other month where we interview someone we find exciting in our industry from a jOOQ perspective. This includes people who work with SQL, Java, Open Source, and a variety of other related topics. I'm very excited to … Continue reading jOOQ Tuesdays: Oliver Gierke Talks About Spring Data