\label{Spreadsheet_Completely_Recalc}
The total number of sheets in course can be tremendous, since it is
the number of students times the number of assessments. LON-CAPA
caches these sheets and only selectively invalidates those cache
copies if potentially relevant data changes. \textbf{Completely
Recalc} forces LON-CAPA to invalidate all cache copies.
\index{Completely Recalc}

For instance, this is necessary to get the most up-to-date
calculations if the sheet itself contains direct access to the system
clock (making it ``out-of-date'' the moment it is calculated), or if
an assessment is edited in a way that would retroactively change
grading. The automatic spreadsheet devalidation catches student
submissions, \textbf{PAR}a\textbf{M}eter changes, and spreadsheet
changes, but not re-publication of a problem resource.