# A Hidden Benefit of Implicit Joins: Join Elimination

DevFeed: [A Hidden Benefit of Implicit Joins: Join Elimination](<https://devfeed.tech/articles/a-hidden-benefit-of-implicit-joins-join-elimination-28930.md>)

Original publisher: [Read original article](<https://blog.jooq.org/a-hidden-benefit-of-implicit-joins-join-elimination/>)

Author: lukaseder

Published: 2024-01-10T14:19:00Z

Content type: article

Language: en

Sources: [jOOQ](<https://devfeed.tech/sources/jooq.md>)

Topics: [SQL](<https://devfeed.tech/topics/sql.md>), [Databases](<https://devfeed.tech/topics/databases.md>), [rdbms](<https://devfeed.tech/topics/rdbms.md>)

Tags: [implicit-joins](<https://devfeed.tech/tags/implicit-joins.md>), [implicit-path-join](<https://devfeed.tech/tags/implicit-path-join.md>), [java](<https://devfeed.tech/tags/java.md>), [join-elimination](<https://devfeed.tech/tags/join-elimination.md>), [jooq](<https://devfeed.tech/tags/jooq.md>), [jooq-3-19](<https://devfeed.tech/tags/jooq-3-19.md>), [jooq-in-use](<https://devfeed.tech/tags/jooq-in-use.md>), [many-to-many-joins](<https://devfeed.tech/tags/many-to-many-joins.md>), [optimisation](<https://devfeed.tech/tags/optimisation.md>), [path-joins](<https://devfeed.tech/tags/path-joins.md>), [sql](<https://devfeed.tech/tags/sql.md>), [to-many-joins](<https://devfeed.tech/tags/to-many-joins.md>)

## AI overview

This article explains how jOOQ 3.19 can eliminate unnecessary tables from implicit path joins when no columns from those tables are referenced. Primary and foreign keys preserve equivalence, while referenced columns cause the table to remain in the join tree. The behavior applies to implicit path joins and depends on a flag that is disabled by default.

## Source excerpt

One of jOOQ's key features so far has always been to render pretty much exactly the SQL that users expect, without any surprises - unless some emulation is required to make a query work, of course. This means that while join elimination is a powerful feature of many RDBMS, it isn't part of jOOQ's feature ... Continue reading A Hidden Benefit of Implicit Joins: Join Elimination ->