Threading (or multiprocessing), performance and refactoring

romjerome · September 8, 2025, 11:34pm

Nothing currently common (python, others applications, etc.) or a limitation to gramps database backends?

github.com/gramps-project/gramps

DBAPI improvements with SQLite implementation

dsb/sqlite-optimizations ← glamberson:fix-doug-sqlite

ouvert 03:04PM - 07 Aug 25 UTC

glamberson

+296 -3

This PR builds on your excellent SQLite optimizations by adding complementary ba…ckend-agnostic improvements to the DBAPI base class. I've kept all your valuable work while organizing things so SQLite-specific code stays in sqlite.py and generic improvements benefit all backends. ## What This Adds ### 1. Real Cursor Support (5 lines, huge memory savings) - Returns iterators for backends that support real cursors (PostgreSQL, MySQL) - Gracefully falls back to regular lists for SQLite/BSDDB - Reduces memory usage by 10x for large databases ### 2. Lazy Loading (Optional, 50% memory reduction) - Returns a proxy that loads person data only when accessed - Dramatically reduces memory for operations that don't need all object data - Completely optional - existing code continues to work ### 3. Improved Prepared Statements (Backend-agnostic) - PostgreSQL/MySQL get real prepared statements - SQLite gets your cached query strings - Same API for all backends ### 4. Batch Operations (Using executemany) - Uses executemany() when available - Falls back to individual commits for other backends - 100x speedup for bulk imports ## What I Preserved All @dsblank 's proposed SQLite optimizations remain intact: - WAL mode, cache settings, memory-mapped I/O - Connection pooling - Your bulk insert/update methods - Performance indexes - JSON query functions ## Organization Changes I moved SQLite-specific code to the SQLite class: - VACUUM now lives in SQLite.optimize_database() - Base DBAPI.optimize_database() only does ANALYZE (widely supported) ## Testing All changes include graceful fallbacks and maintain backward compatibility. The improvements are additive - existing code continues to work exactly as before. ## Impact Combined with your optimizations: - Your changes: 2-10x performance improvement - These additions: 10x memory reduction, 2x query performance - Together: Makes Gramps viable for 100,000+ person databases Let me know if you'd like any adjustments or have questions about the implementation\! Best, Greg

About Gramps 6 installation, I need a large OS upgrade, before…

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Threading (or multiprocessing), performance and refactoring

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