y no conflicting live tuple, we
   are done.  Otherwise, we schedule a recheck to occur when it is time to
   enforce the constraint.  If, at the time of the recheck, both the inserted
   tuple and some other tuple with the same key are live, then the error
   must be reported.  (Note that for this purpose, <SPAN
CLASS="QUOTE"
>"live"</SPAN
> actually
   means <SPAN
CLASS="QUOTE"
>"any tuple in the index entry's HOT chain is live"</SPAN
>.)
   To implement this, the <CODE
CLASS="FUNCTION"
>aminsert</CODE
> 