Error
Error Code:
3973
MySQL Error 3973: Subquery Transformation Conflict
Description
This error indicates that the MySQL optimizer attempted to apply a specific subquery transformation (e.g., converting an IN subquery to an EXISTS clause or a subquery to a LATERAL derived table), but this transformation was rejected because the 'subquery_to_derived' optimizer switch was enabled. It typically occurs when a complex query involves subqueries that trigger conflicting optimization strategies.
Error Message
Statement requires a transform of a subquery to a non-SET operation (like IN2EXISTS, or subquery-to-LATERAL-derived-table). This is not allowed with optimizer switch 'subquery_to_derived' on
Known Causes
3 known causesConflicting Optimizer Switches
The 'subquery_to_derived' optimizer switch is enabled, which forces subqueries to be materialized, but the query simultaneously requires a different subquery transformation (like IN2EXISTS) that is incompatible with this setting.
Complex Subquery Structure
The specific structure or complexity of a subquery within your statement might trigger an optimizer attempt to perform a transformation that clashes with the 'subquery_to_derived' setting.
Specific MySQL Version Behavior
Certain MySQL versions or patches might have specific optimizer behaviors or bugs that lead to this conflict under particular query patterns.
Solutions
Coming SoonDetailed step-by-step solutions for this error are being prepared. In the meantime, try these general troubleshooting tips:
General Troubleshooting Tips
- Check the error message carefully for specific details
- Review recent changes that might have caused the error
- Search for the exact error code in the official documentation
- Check log files for additional context
- Try restarting the application or service