[LON-CAPA-cvs] cvs: loncom /html/adm/help/tex Statistics_Cache.tex doc/loncapafiles loncapafiles.lpml

[matthew]

matthew		Fri Jun 25 16:32:50 2004 EDT

  Added files:                 
    /loncom/html/adm/help/tex	Statistics_Cache.tex 

  Modified files:              
    /doc/loncapafiles	loncapafiles.lpml 
  Log:
  Added Statistics_Cache.tex, help file describing the statistics caches
  and what the cache management buttons do.
  
  
Index: doc/loncapafiles/loncapafiles.lpml
diff -u doc/loncapafiles/loncapafiles.lpml:1.367 doc/loncapafiles/loncapafiles.lpml:1.368
--- doc/loncapafiles/loncapafiles.lpml:1.367	Mon Jun 21 10:11:18 2004
+++ doc/loncapafiles/loncapafiles.lpml	Fri Jun 25 16:32:49 2004
@@ -2,7 +2,7 @@
  "http://lpml.sourceforge.net/DTD/lpml.dtd">
 <!-- loncapafiles.lpml -->
 
-<!-- $Id: loncapafiles.lpml,v 1.367 2004/06/21 14:11:18 matthew Exp $ -->
+<!-- $Id: loncapafiles.lpml,v 1.368 2004/06/25 20:32:49 matthew Exp $ -->
 
 <!--
 
@@ -2570,6 +2570,7 @@
 Spreadsheet_Ternary_Operator.tex;
 Spreadsheet_Tries.tex;
 Statistics_Overall_Key.tex;
+Statistics_Cache.tex;
 String_Response_Problem_Creation.tex;
 String_Response_Problems.tex;
 Syllabus_ExtLink.tex;

Index: loncom/html/adm/help/tex/Statistics_Cache.tex
+++ loncom/html/adm/help/tex/Statistics_Cache.tex
\label{Statistics_Cache}

The \textbf{\index{Statistics Cache}Statistics Cache} manages the data 
used in computing student performance statistics.

Much of the time spent computing statistics is actually used to
compile student data into a more useful format, the temporary course
cache.  Normally student data is maintained in an archived format
which does not provide for rapid access.  Since each student's data is
stored on their home server in their account, and not with the course,
it takes time to compile the data and store it in the temporary course
cache.  All of the statistics modes use the same cache so the process
of compiling the student data does not need to be repeated when
successive statistics are requested.

Only those students who are involved in the current calculation will
have their data compiled.  When you modify the selected set of
students, by changing the section you are computing statistics with,
the caches will be updated.

The temporary course cache is maintained for 2 days on the server used
for the statistics computation.

The cache management buttons, marked \textbf{Clear Caches} and
\textbf{Update Caches}, appear when the temporary course caches are in
use.  \textbf{Clear Caches} causes the entire cache for the course to
be flushed, discarding all the current contents.  The cache is then
rebuilt to display the desired statistics.  The normal use of
statistics should not require you to press this button, but it is here
for completeness.

\textbf{Update Caches} checks the students record for updates since their 
data was compiled.  Any changes to the student's record for your
course will be reflected after this button has been pressed.  The
\textbf{Update Caches} button is useful if your students are currently
completing a homework set and you wish to evaluate their progress in
the time your statistics were generated.