Configuration & Runtime Options

src/config/ centralizes tunables used by DatabaseOptions, the CLI/HTTP front-ends, and background workers. Keeping knobs in one place makes it easy to demonstrate how WAL, buffering, or vacuum behavior changes under different settings.

Key Types

Type	Description
`DatabaseOptions`	Top-level options when constructing a database (WAL config, default isolation, etc.).
`WalOptions`	WAL directory, segment size, flush strategy, writer interval, sync mode.
`IndexVacuumConfig` / `MvccVacuumConfig`	Background worker intervals (buffer writer, MVCC vacuum).
`BufferPoolConfig`	Optional overrides for pool size, TinyLFU, and replacement policy details.

Usage

CLI/HTTP front-ends parse env vars or config files into DatabaseOptions and pass them to Database::new_*.
During bootstrap_storage, the database wires these options into WalManager, DiskScheduler, and BackgroundWorkers.
Workers and execution components receive Arc references to the relevant configs so they can adapt at runtime without global state.

Teaching Ideas

Toggle WalOptions::synchronous_commit to discuss commit latency vs durability.
Shrink the buffer pool to highlight eviction behavior under different replacement policies.
Adjust MvccVacuumConfig intervals and measure how vacuum frequency affects foreground write throughput.