Function execute_scan_host 

pub unsafe fn execute_scan_host(
    base: *mut u8,
    plan: &ScanBodyPlan,
    outer_init_off: usize,
    outer_final_off: usize,
    length: u32,
    save_trajectory: bool,
    xs_outer: &[(usize, usize)],
    bcast_outer: &[(usize, usize)],
)

Execute a compiled scan body over length steps against a raw arena buffer base. outer_init_off / outer_final_off are byte offsets into that arena; xs_outer[i] = (outer_off, per_step_bytes) and bcast_outer[i] = (outer_off, total_bytes) align with the plan’s xs_body_offs / bcast_body_offs. When save_trajectory, row t is written to outer_final_off + t * carry_bytes (every step; checkpointed scans are not supported via this path).

Safety

base must point to a valid arena spanning every referenced offset.