[WWdevel] relative speed of sql_single and gdbm

[Arnold P. <ap...@ma...>]

Hi,

I'm trying to get some idea of the relative speed of sql_single and gdbm and
have been looking at our timing log.   This is prompted by some of my students
reaction that WeBWorK is slower this semester than last.  Last semester all
courses (except MTH 162 which used sql) used gdbm.  This semester all courses
are using sql_single. It seems gdbm is the fastest, then sql_single, and then
sql.  Also sql and sql_single have many more times that are long compared to
gdbm.  The details are below but here is a snap shot:

For gdbm

68% of the gdbm entires took 0.0 seconds (the log rounds to 1 second)
29% of the gdbm entires took 1.0 seconds
0.01% of the gdbm entires took 10.0 seconds

For sql_single the percentages were:

52%
34%
1.7%

and for sql

40%
31%
3%

This data came from our timing log which covers Oct 16, 2004 through Feb 3, 
2005
(data before Oct 16 were in a different format)

I'm not sure what we can do with this data but we should be aware of 
it.  Also I
don't know how BerkelyDB would compare. Bill Wheeler is using that for both
WW1.9 and WW2 at Indiana.

Arnie

Here's the actual data:

There were 702291 total timings for gdbm, 441585 for sql and
290963 for sql_single.

grep '0.0 sec gdbm' timing.02_03_05 | wc -l gives the first entry, etc.

476652  0.0 sec gdbm
205360  1.0 sec gdbm
  10644  2.0 sec gdbm
   4936          3.0 sec gdbm
   1058          4.0 sec gdbm
   1177          5.0 sec gdbm
   1784          6.0 sec gdbm
    404          7.0 sec gdbm
    153          8.0 sec gdbm
    123          9.0 sec gdbm
     69          10.0 sec gdbm
     58          11.0 sec gdbm
     26          12.0 sec gdbm
     20          13.0 sec gdbm
     23          14.0 sec gdbm
     46          15.0 sec gdbm
     24          16.0 sec gdbm
     14          17.0 sec gdbm
     12          18.0 sec gdbm
      5          19.0 sec gdbm
     14          20.0 sec gdbm


grep '0.0 sec sql_single' timing.02_03_05 | wc -l gives the first entry, etc.

150926  0.0 sec sql_single
100426  1.0 sec sql_single
  22972  2.0 sec sql_single
   7179          3.0 sec sql_single
   3358          4.0 sec sql_single
   2082          5.0 sec sql_single
   1486          6.0 sec sql_single
   1053          7.0 sec sql_single
    840          8.0 sec sql_single
    641          9.0 sec sql_single
    484          10.0 sec sql_single
    374          11.0 sec sql_single
    289          12.0 sec sql_single
    207          13.0 sec sql_single
    190          14.0 sec sql_single
    162          15.0 sec sql_single
    145          16.0 sec sql_single
    129          17.0 sec sql_single
    129          18.0 sec sql_single
     89          19.0 sec sql_single
     94          20.0 sec sql_single


grep '0.0 sec sql' timing.02_03_05 | wc -l gives the first entry, etc.


   175395        0.0 sec sql
   135452        1.0 sec sql
    35487        2.0 sec sql
    35450        3.0 sec sql
    30331        4.0 sec sql
    12301        5.0 sec sql
     6750        6.0 sec sql
     4583        7.0 sec sql
     3286        8.0 sec sql
     2550        9.0 sec sql
     1657        10.0 sec sql
     1306        11.0 sec sql
      992        12.0 sec sql
      758        13.0 sec sql
      682        14.0 sec sql
      565        15.0 sec sql
      530        16.0 sec sql
      479        17.0 sec sql
      397        18.0 sec sql
      325        19.0 sec sql
      271        20.0 sec sql


Prof. Arnold K. Pizer
Dept. of Mathematics
University of Rochester
Rochester, NY 14627
(585) 275-7767