Senior LevelSQL & MySQL
How does Dynamic Partition Pruning optimize partitioned table join performance?
❓ Interview Prompt: Explain Static vs Dynamic Partition Pruning, subquery join pruning, and optimizing range-partitioned tables.
Partition Pruning skips reading non-matching partition files during query execution:
Static vs Dynamic Pruning:
•
Static Partition Pruning: Filter values are known at compile time ('WHERE sale_date = '2026-01-15'').
•
Dynamic Partition Pruning: Filter values are evaluated dynamically at runtime during join operations ('WHERE p.sale_date = d.calendar_date'). The engine prunes partitions on-the-fly as join keys are evaluated!
Code Implementation Example
sql
-- Query benefiting from Dynamic Partition Pruning during table join
EXPLAIN SELECT s.id, s.amount, d.month_name
FROM sales s
JOIN dim_date d ON s.sale_date = d.full_date
WHERE d.year = 2026; -- Prunes sales partitions dynamically at runtime!💡Verifying Dynamic Partition Pruning execution plan via EXPLAIN.
🎯 Interview Key Takeaway
Ensure join keys align with partition keys to enable Dynamic Partition Pruning and reduce disk I/O.
#SQL#Partition Pruning#Dynamic Pruning#Performance#Senior
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