LGTM.

> diff --git a/src/box/sql/insert.c b/src/box/sql/insert.c
> index 3c3bf37..4f52fa5 100644
> --- a/src/box/sql/insert.c
> +++ b/src/box/sql/insert.c
> @@ -1869,7 +1869,7 @@ xferOptimization(Parse * pParse,	/* Parser context */
>  	 * table (tab1) is initially empty.
>  	 */
>  
> -	/* The Vdbe we're building*/
> +	/* The Vdbe struct we're building. */

You misunderstood me. What I mean is:

struct Vibe *v = …;

>  	Vdbe *v = sqlite3GetVdbe(pParse);