N+1 queries are a popular problem in many applications that run SQL queries. The problem can be described easily as follows: 1 query fetching a parent value is runN queries fetching each individual child values are run This problem isn't limited to SQL, it can happen with any poorly designed API that does not allow … Continue reading Using jOOQ’s DiagnosticsConnection to detect N+1 Queries
The Useful BigQuery * EXCEPT Syntax
One of the coolest things about using and making jOOQ is that we get to discover the best extensions to the standard SQL language by vendors, and add support for those clauses in jOOQ via emulations. One of these syntaxes is BigQuery's * EXCEPT syntax. Everyone who ever wrote ad-hoc SQL queries would have liked … Continue reading The Useful BigQuery * EXCEPT Syntax
3.16.0 Release with a new Public Query Object Model API, Spatial Support, YugabyteDB Support and Much More
This release tackles two long standing and complex feature requests that usershave asked us to offer for a long time: a public API for manipulating jOOQ'squery object model (QOM), and spatial support. New Query Object Model (QOM) Every jOOQ query is modeled as an expression tree constructed via our intuitiveDSL. For some use-cases there exist … Continue reading 3.16.0 Release with a new Public Query Object Model API, Spatial Support, YugabyteDB Support and Much More
How to customise a jOOQ Configuration that is injected using Spring Boot
Starting from Spring Boot 2.5, there's a handy new callback that you can implement, called DefaultConfigurationCustomizer, where the word DefaultConfiguration corresponds to jOOQ's DefaultConfiguration. You can simply create a class like this in your project: import org.jooq.conf.RenderQuotedNames; import org.jooq.impl.DefaultConfiguration; import org.springframework.boot.autoconfigure.jooq.*; import org.springframework.context.annotation.*; @Configuration public class Config { @Bean public DefaultConfigurationCustomizer configurationCustomiser() { return (DefaultConfiguration … Continue reading How to customise a jOOQ Configuration that is injected using Spring Boot
Using JDK Collectors to De-duplicate parent/child nested collections
In classic SQL (i.e. before jOOQ's awesome MULTISET operator), nested collections were fetched using ordinary (outer) joins. An example of such a query would be a query running against the sakila database to fetch actors and their films. Using jOOQ: Result<?> result = ctx.select( ACTOR.ACTOR_ID, ACTOR.FIRST_NAME, ACTOR.LAST_NAME, FILM.FILM_ID, FILM.TITLE) .from(ACTOR) .leftJoin(FILM_ACTOR).on(ACTOR.ACTOR_ID.eq(FILM_ACTOR.ACTOR_ID)) .leftJoin(FILM).on(FILM_ACTOR.FILM_ID.eq(FILM.FILM_ID)) .orderBy( ACTOR.ACTOR_ID, FILM.FILM_ID) … Continue reading Using JDK Collectors to De-duplicate parent/child nested collections
Why You Should Use jOOQ With Code Generation
I'm answering many jOOQ questions on Stack Overflow, and a lot of times. The problem has the same cause: People not using jOOQ's code generator. The main reason people seem not to be using it, is because it takes some extra time to set up, but as with anything well designed, the initial investment will … Continue reading Why You Should Use jOOQ With Code Generation
Fun with PostGIS: Mandelbrot Set, Game of Life, and More
The upcoming jOOQ 3.16 will finally offer support for the various RDBMS GIS extensions via issue #982. This is great news per se, and will be covered in a future blog post, when the integration is ready. This post here is about something else. Adding support for such a feature is a great source of … Continue reading Fun with PostGIS: Mandelbrot Set, Game of Life, and More
PostgreSQL 14’s enable_memoize For Improved Performance of Nested Loop Joins
I've recently discovered a pleasant new addition to PostgreSQL 14, the new enable_memoize flag that improves the performance of some nested loop joins where statistics hint at this being appropriate. I mean, who can resist this temptation: https://twitter.com/RPorsager/status/1455660236375826436 Improving query speed by 1000x hints at something very suboptimal having been going on before, and a … Continue reading PostgreSQL 14’s enable_memoize For Improved Performance of Nested Loop Joins
Java’s Checked Exceptions Are Just Weird Union Types
This fun fact has been on my mind for a while, and a recent reddit thread about "Smuggling Checked Exceptions with Sealed Interfaces" made me write this post here. Namely, Java had union types before it was cool! (If you squint hard). What are union types? Ceylon is an underrated JVM language that never really … Continue reading Java’s Checked Exceptions Are Just Weird Union Types
Functional Dependencies in SQL GROUP BY
The SQL standard knows an interesting feature where you can project any functional dependencies of a primary (or unique) key that is listed in the GROUP BY clause without having to add that functional dependency to the GROUP BY clause explicitly. What does this mean? Consider this simple schema: CREATE TABLE author ( id INT … Continue reading Functional Dependencies in SQL GROUP BY