[toygres] Postgres parameter configuration

[affandar]

Repository

affandar/toygres

Concept

Allow users to configure Postgres parameters and apply them dynamically or with restart.

Parameter Categories

• Dynamic: Can be changed without restart (SET command)
• Reload: Requires pg_reload_conf()
• Restart: Requires Postgres restart
• Immutable: Cannot be changed after init

API

// Set parameters
client.set_parameters(SetParametersRequest {
    instance_id: "pg-prod-1".into(),
    parameters: vec![
        ("shared_buffers".into(), "4GB".into()),
        ("work_mem".into(), "256MB".into()),
        ("max_connections".into(), "200".into()),
    ],
    apply_mode: ApplyMode::Immediate,  // or Scheduled, OnNextRestart
}).await?;

// Get current parameters
let params = client.get_parameters("pg-prod-1").await?;

Apply Modes

• Immediate: Apply now (may restart if needed)
• Scheduled: Apply at specified time
• OnNextRestart: Apply when instance next restarts

Parameter Profiles

Pre-defined profiles for common workloads:

• OLTP: Optimized for transactional workloads
• Analytics: Optimized for OLAP
• GeneralPurpose: Balanced for mixed workloads
• Development: Minimal resources

client.apply_parameter_profile(ApplyProfileRequest {
    instance_id: "pg-prod-1".into(),
    profile: ParameterProfile::Oltp,
    override_params: vec![("max_connections".into(), "500".into())],
}).await?;

See: proposals/toygres-improvements.md