/**
 * Apply SQLite performance pragmas to the CAP db service.
 *
 * Default SQLite settings prioritise crash-safety over throughput. For an
 * indexer doing many small write transactions during catch-up, these
 * defaults bottleneck on per-commit fsync. The pragmas below are the
 * standard "warm read-heavy / write-once-then-reindex" tuning used by
 * Substrate indexers, btc explorers, etc.
 *
 * Safety: with `journal_mode=WAL` (already set by @cap-js/sqlite for
 * file-based DBs) and `synchronous=NORMAL`, the WAL is durable on commit
 * but the WAL header isn't fsynced per transaction. The risk window is
 * a power loss between commit and the periodic checkpoint, in which case
 * the last few uncommitted-to-disk transactions are lost. An indexer
 * tolerates this trivially: it just re-fetches the missing blocks from
 * the node on next start.
 *
 * No-op for non-SQLite databases (HANA in prod doesn't expose `.pragma`).
 */
export declare function applySqliteTuning(db: any): Promise<void>;
