Lukas Eder is a SQL expert and creator of jOOQ who writes in-depth articles on SQL standards, database performance, and advanced query design. His blog focuses on practical and theoretical aspects of modern relational databases.
50 articles from this blog
Explores using JSON arrays over objects for serialization in jOOQ's MULTISET operator, focusing on performance and reliability.
Explores SQL array functions and the integration of lambda expressions in modern SQL dialects like ClickHouse and DuckDB for filtering and transforming array data.
Explains the SQL MERGE statement by comparing it to a RIGHT JOIN, showing how to think about source and target tables in ETL operations.
A product manager argues against excessive documentation, explaining why linking unrelated features can create clutter and maintenance issues.
jOOQ 3.20 released with new SQL dialect support for ClickHouse and Databricks, expanded DuckDB features, and various new modules and improvements.
Explains how to emulate SQL's FILTER clause for JSON aggregate functions in Oracle, addressing NULL value handling in JSON arrays and objects.
Explains Oracle-specific SQL techniques for retrieving the top 1 row per group, covering KEEP syntax, ANY_VALUE(), and object/JSON workarounds.
Explains a performance optimization technique for checking multiple row existence in SQL using LIMIT clauses, with benchmarks across RDBMS.
Explains how jOOQ 3.19's implicit joins can automatically eliminate unnecessary table joins from SQL queries, improving performance.
jOOQ 3.19 introduces new explicit and implicit to-many path joins, simplifying SQL query syntax and improving readability and correctness.
Explains a common MySQL UPDATE error and provides a workaround using a derived table or jOOQ to bypass the restriction.
jOOQ 3.19.0 release adds support for DuckDB, Trino, Oracle 23c, introduces join path improvements, an official Gradle plugin, and commercial Maven repositories.
A reference list of Maven coordinates (groupId and artifactId) for the most popular JDBC drivers, sourced from jOOQ integration tests.
Discusses the pros and cons of using jOOQ's DAO API versus writing explicit SQL, highlighting the risk of N+1 problems.
A reference list of JDBC driver names and connection URL formats for numerous popular relational database management systems (RDBMS).
A guide on configuring jOOQ's code generator to produce package-private Java classes for better encapsulation.
A technical guide on using jOOQ to pass table-valued parameters (TVPs) to T-SQL functions from Java, with code examples.
A tutorial on converting flat data into hierarchical structures using SQL, Java, and the jOOQ library's new features.
jOOQ 3.18.0 release adds enhanced SQL diagnostics, SQL/JSON support, Oracle/PostgreSQL array features, and R2DBC 1.0 integration.
Explains a caveat with using jOOQ's ad-hoc converters in UNION operations and provides solutions for proper client-side type conversion.
