Setting the JDBC Statement.setFetchSize() to 1 for Single Row Queries

An interesting hint by Vladimir Sitnikov has made me think about a new benchmark for jOOQ: https://twitter.com/lukaseder/status/1407662449331949568 The benchmark should check whether single row queries should have a JDBC Statement.setFetchSize(1) call made to them by default. The Javadoc of the method says: Gives the JDBC driver a hint as to the number of rows that … Continue reading Setting the JDBC Statement.setFetchSize() to 1 for Single Row Queries

Use MULTISET Predicates to Compare Data Sets

Questions that might be a bit more difficult to solve using ordinary SQL are questions of the kind: What films have the same actors as a given film X? As always, we're using the sakila database for this example. What would be a possible way to solve this with SQL (for example, PostgreSQL, to be … Continue reading Use MULTISET Predicates to Compare Data Sets

Projecting Type Safe Nested TableRecords with jOOQ 3.17

A long standing feature request has seen little love from the jOOQ community, despite a lot of people probably wanting it. It goes by the unimpressive title Let Table<R> extend SelectField<R>: https://github.com/jOOQ/jOOQ/issues/4727 What does the feature mean, specifically? The awesome PostgreSQL Let's have a look at a really cool PostgreSQL feature. In PostgreSQL, it is … Continue reading Projecting Type Safe Nested TableRecords with jOOQ 3.17

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

Using Testcontainers to Generate jOOQ Code

Database first is at the core of jOOQ's design. jOOQ has been made primarily for classic systems the database is always there and always has been and will never leave. This is because we think "data have mass" https://twitter.com/ChrisRSaxon/status/1093122970254536704 This not only translates to moving logic closer to the data (see our previous posts about … Continue reading Using Testcontainers to Generate jOOQ Code

Vendor Agnostic, Dynamic Procedural Logic with jOOQ

One of the strengths of modern RDBMS is the capability to mix the powerful SQL language with procedural code. SQL is a 4th generation programming language (4GL), and as such, extremely well suited for querying and bulk data manipulation. Its functional-declarative nature allows for it to be optimised in highly efficient ways using cost-based optimisation, … Continue reading Vendor Agnostic, Dynamic Procedural Logic with jOOQ

Standard SQL/JSON – The Sobering Parts

It's been almost 1 year now since jOOQ 3.14 was released in October 19, 2020 with SQL/JSON (and SQL/XML) support. Half a year later, we've released jOOQ 3.15 with MULTISET support, which builds on top of these features to offer type-safe nested collections, the way every ORDBMS should implement them. Building (dogfooding) on top of … Continue reading Standard SQL/JSON – The Sobering Parts

jOOQ 3.15’s New Multiset Operator Will Change How You Think About SQL

This is how SQL should have been used all along. They called it The Third Manifesto, ORDBMS, or other things. Regrettably, it never really took off. Because most vendors didn't adopt it. And those who did, didn't agree on syntax. But this is about to change. Thanks to the now ubiquitous SQL/JSON support (which jOOQ … Continue reading jOOQ 3.15’s New Multiset Operator Will Change How You Think About SQL

Simulating Latency with SQL / JDBC

I've run across a fun little trick to simulate latency in your development environments when testing some SQL queries. Possible use-cases including to validate that backend latency won't bring down your frontend, or that your UX is still bearable, etc. https://twitter.com/gunnarmorling/status/1361061234569805832 The solution is PostgreSQL and Hibernate specific, though to doesn't have to be. Besides, … Continue reading Simulating Latency with SQL / JDBC

Implementing a generic REDUCE aggregate function with SQL

So, @rotnroll666 nerd sniped me again. Apparently, the Neo4j Cypher query language supports arbitrary reductions, just like any functional collection API, oh say, the JDK Stream API: Stream.of(2, 4, 3, 1, 6, 5) .reduce((i, j) -> i * j) .ifPresent(System.out::println); // Prints 720 SQL doesn't have this, yet it would be very useful to be … Continue reading Implementing a generic REDUCE aggregate function with SQL