Feature Flags

Toggle individual features on and off at runtime without restarting.

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Overview

Feature flags let you enable or disable features at runtime. Useful for A/B testing, gradual rollouts, and emergency feature kills.

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Available Flags

Flag	Description	Default
BinarySerialization	Binary serialization	Off
MultiThreading	Multi-threaded execution	Off
MvccExtension	MVCC extended features	Off
QueryPlanCache	Query plan cache	Off
ParallelQuery	Parallel query execution	Off
ParallelWal	WAL parallel writes	Off
ParallelCheckpoint	Parallel checkpoint	Off
SchemaVersioning	Schema versioning	Off
IndexVersioning	Index versioning	Off

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Usage

use dbx_core::engine::feature_flags::{FeatureFlags, Feature};

let flags = FeatureFlags::new();

// Enable/disable features
flags.enable(Feature::ParallelQuery);
flags.disable(Feature::ParallelQuery);
flags.toggle(Feature::QueryPlanCache);

// Check status
if flags.is_enabled(Feature::ParallelQuery) {
    // parallel query execution path
}

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Persistence

File Save/Load

// Save to JSON file
flags.save_to_file("./dbx_features.json")?;

// Load from file
let flags = FeatureFlags::load_from_file("./dbx_features.json")?;

Environment Variables

Control features via environment variables:

export DBX_FEATURE_PARALLEL_QUERY=true
export DBX_FEATURE_QUERY_PLAN_CACHE=true

let flags = FeatureFlags::load_from_env();

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Use Cases

Scenario	Approach
Gradual feature rollout	enable on selected servers
Emergency performance fix	disable ParallelQuery
Per-environment config	Separate JSON files for dev/staging/prod
CI test isolation	Test feature combinations via env vars

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Next Steps

• Parallel Query Guide — Detailed parallel query configuration
• Plan Cache Guide — Cache feature toggle