Clik here to view.
Calculating Pagination Metadata Without Extra Roundtrips in SQL
When paginating results in SQL, we use standard SQL OFFSET .. FETCH or a vendor specific version of it, such as LIMIT .. OFFSET. For example: SELECT first_name, last_name FROM actor ORDER BY actor_id...
View ArticleUse IN List Padding to Your JDBC Application to Avoid Cursor Cache Contention...
A problem few developers are aware of is the possibility of running into “cursor cache contention” or “execution plan cache contention” problems when using IN lists in SQL. The problem that is...
View ArticleHow to Get an RDBMS Server Version with SQL
Do you need to know what RDBMS Server version you’re on, and you only have SQL at your disposal? No problem. Most RDBMS provide you with that information in some form of meta data table. Here’s how:...
View ArticlejOOQ 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...
View ArticleReactive SQL with jOOQ 3.15 and R2DBC
One of the biggest new features of the recently released jOOQ 3.15 is its new support for reactive querying via R2DBC. This has been a highly popular feature request, and we finally delivered on it....
View ArticleStandard 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...
View ArticleFormatting ASCII Charts With jOOQ
A very little known feature in jOOQ is the Formattable.formatChart() capability, which allows for formatting any jOOQ result as an ASCII chart. This can be useful for quick plotting of results in your...
View ArticleVendor 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...
View ArticleThe jOOQ Parser Ignore Comment Syntax
jOOQ’s parser can’t parse every possible SQL syntax. Try this random PostgreSQL syntax: ALTER SYSTEM RESET ALL And the jOOQ parser will complain: DOMAIN, INDEX, SCHEMA, SEQUENCE, SESSION, TABLE, TYPE,...
View ArticleFunctional 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...
View ArticleClik here to view.
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....
View ArticleClik here to view.
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...
View ArticleClik here to view.
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...
View ArticleThe 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....
View ArticleUsing jOOQ’s DiagnosticsConnection to detect N+1 Queries
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...
View ArticleA Rarely Seen, but Useful SQL Feature: CORRESPONDING
I recently stumbled upon a standard SQL feature that was implemented, to my surprise, in HSQLDB. The keyword is CORRESPONDING, and it can be used with all set operations, including UNION, INTERSECT,...
View ArticleApproximating e With SQL
If you’re running on PostgreSQL, you could try the following cool query: WITH RECURSIVE r (r, i) AS ( SELECT random(), i FROM generate_series(1, 1000000) AS t (i) ), s (ri, s, i) AS ( SELECT i, r, i...
View ArticleUse 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...
View ArticleVarious Meanings of SQL’s PARTITION BY Syntax
For SQL beginners, there's a bit of an esoteric syntax named PARTITION BY, which appears all over the place in SQL. It always has a similar meaning, though in quite different contexts. The meaning is...
View ArticleHow to Fetch Sequence Values with jOOQ
A lot of RDBMS support standard SQL sequences of some form. The standard SQL syntax to create a sequence is: CREATE SEQUENCE s; The following is how you could fetch a value from this sequence, using...
View Article