/**
 * Metadata key written onto rewritten fields to preserve the original
 * `Duration` time unit. Consumed by
 * `lib/result/ArrowResultConverter.ts` Phase 1 to choose the correct
 * scale when formatting INTERVAL DAY-TIME values.
 */
export declare const DURATION_UNIT_METADATA_KEY = "databricks.arrow.duration_unit";
/**
 * Walk an IPC stream payload and rewrite any `Duration` field in the
 * schema message to `Int64` (preserving the original time unit in
 * custom metadata). Subsequent record-batch messages are forwarded
 * verbatim — the data layout matches the rewritten `Int64` type
 * bit-for-bit.
 *
 * If the schema contains no `Duration` fields, the input buffer is
 * returned unchanged (zero-copy fast path).
 *
 * The caller is expected to pass a complete IPC stream payload (the
 * full byte buffer the kernel returned for one `fetchNextBatch` call,
 * or the schema-only payload from `statement.schema()`). Multi-segment
 * stream payloads are supported; we walk through each message until
 * the buffer is exhausted.
 *
 * @param ipcBytes raw IPC stream bytes from the napi binding
 * @returns either the original buffer (no rewrite needed) or a fresh
 *   buffer with the schema message replaced
 */
export declare function rewriteDurationToInt64(ipcBytes: Buffer | Uint8Array): Buffer;