async fn delete_index_and_purge(
index_id: RegionIndexId,
access_layer: &AccessLayerRef,
cache_manager: &Option<CacheManagerRef>,
) -> Result<()>async fn delete_index_and_purge(
index_id: RegionIndexId,
access_layer: &AccessLayerRef,
cache_manager: &Option<CacheManagerRef>,
) -> Result<()>