JOIN hints
Applies to ✅ Open Source Edition ✅ Express Edition ✅ Professional Edition ✅ Enterprise Edition
By default, a JOIN operator can be implemented in multiple ways by an RDBMS. The chosen algorithm is vendor specific, and not specified in the SQL standard, as long as it correctly implements the correct JOIN semantics.
Sometimes, however, you may want to hint a more optimal algorithm to your RDBMS with a "join hint." The following sections show how to do that with jOOQ.
In modern RDBMS, hinting is almost never necessary. A hint that may work for a given data set (size, distribution, etc.) may not work well for tomorrow's data anymore. Be very careful when hinting join algorithms, and use this tool only as a last resort. There are often better ways to tune your SQL.
JOIN hints are only available for:
-
INNER JOIN -
LEFT JOIN -
RIGHT JOIN -
FULL JOIN
Table of contents
- 3.10.3.13.1.
- HASH JOIN (new)
- 3.10.3.13.2.
- LOOP JOIN (new)
- 3.10.3.13.3.
- MERGE JOIN (new)
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