o miss removing index entries
      that it should remove.  After the corresponding table rows are removed,
      the dangling index entries would cause errors (such as <SPAN
CLASS="QUOTE"
>"could not
      read block N in file ..."</SPAN
>) or worse, silently wrong query results
      after unrelated rows are re-inserted at the now-free table locations.
      This bug has been present since release 8.2, but occurs so infrequently
      that it was not diagnosed until now.  If you have reason to suspect
   