Show Subqueries for SET and JOIN in EXPLAIN Result

Why it matters

This feature improves query diagnostics by showing subqueries embedded in SET assignments and JOIN conditions when using EXPLAIN. It helps users understand query execution plans more comprehensively, aiding optimization and debugging.

How to use it

Users simply run the EXPLAIN command on queries containing SET or JOIN with subqueries. The EXPLAIN output will now include details of these subqueries automatically, requiring no additional configuration.