Performance Tuning

Optimize database throughput, query latency, index usage, and memory overhead in iOS and macOS apps.

BoutiqueDB provides low-latency database operations powered by the Rust Turso engine. Follow these tuning techniques to maximize performance in high-throughput applications.

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Indexing & Query Latency

Ensure columns used in WHERE, ORDER BY, or JOIN clauses have supporting indexes.

Indexes.swift

try conn.execute("""
    CREATE INDEX IF NOT EXISTS idx_task_completed_date 
    ON task_item (isCompleted, dueDate DESC)
""")

Index Verification: Run EXPLAIN QUERY PLAN on complex queries during development to verify index usage and eliminate full-table scans.

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Write Performance & Busy Retries

When multiple background tasks perform concurrent database writes, configure TursoOpenOptions to optimize write queueing:

let options = TursoOpenOptions(
    busyTimeout: .seconds(5) // Wait up to 5s during write lock contention
)

let db = try await BoutiqueDB.open(url: storeURL, options: options)

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Multi-Process WAL Optimization

For apps utilizing App Extensions (e.g. Share Extensions, WidgetKit, or Background Tasks), enable Multi-Process WAL mode:

MultiProcess.swift

let options = TursoOpenOptions(
    multiProcessWAL: true
)

App Group Location: Multi-Process WAL databases must reside within a shared App Group container URL so both the main app and extensions can access the shared memory .shm and .wal files.