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4.3.3. Spark Performance Optimization

💡 First Principle: Spark performance depends on parallelism (partition count), data locality (caching), and resource utilization (executor configuration). Optimizing one dimension while ignoring others produces limited improvement.

Key Optimization Techniques

TechniquePurposeWhen to Use
Dynamic AllocationRight-size executor countVariable workloads
CachingKeep frequently accessed data in memoryIterative processing
Broadcast JoinAvoid shuffle for small tablesJoining large + small tables
Partition PruningSkip irrelevant partitionsFiltered queries

Native Execution Engine

  • Concept: Fabric's optimized Spark engine for common operations
  • Benefit: Significant performance improvement for supported operations
  • Limitation: Does not support User-Defined Functions (UDFs)

⚠️ Exam Trap: Using UDFs with native execution engine causes fallback to traditional Spark. If using UDFs, expect performance regression compared to native-supported operations. Questions about "slow UDF performance" are testing this knowledge.

Alvin Varughese
Written byAlvin Varughese
Founder15 professional certifications