Comprehensive and Detailed Explanation From Exact Extract:

Pega’s performance optimization techniques, as taught in Pega Academy’sPerformance Optimization Missionand thePega Certified Lead System Architect Study Guide, focus on reducing database load and improving query efficiency. Archival and indexing are standard approaches for managing high data volumes.

Option A (Incorrect): Horizontal and vertical database partitioning and replication are advanced database techniques that require significant DBA effort and may not be supported in Pega’s managed environments (e.g., Pega Cloud). They are less practical than Pega-specific solutions, per theDatabase Optimizationmodule.

Option B (Correct): Archiving cases, case history, and media files, followed by purging based on usage patterns, reduces database size and improves performance. Pega’s Archival and Purge tools are designed for this purpose, as documented in theData Archivalsection of Pega Community.

Option C (Incorrect): Database defragmentation is not a Pega-specific solution and is typically managed by DBAs outside the application. It is less impactful than archival or indexing for Pega performance, per thePerformance Tuningguidelines.

Option D (Correct): Indexing critical tables and optimizing columns (e.g., adding indexes on frequently queried fields) significantly improves query performance.This is a recommended Pega practice, as noted in theDatabase Indexingmodule.