Re: [OpenWeBWorK-devel] Fwd: timing data on WW2.1 (HEAD as of 10.16.2004)

[John J. <jj...@as...>]

This is interesting data.  I have a few thoughts/questions.

Does anyone have an explanation as to why sql_single would beat sql?  
Naively I would expect it to always be the other way around (or end up 
in ties).  More information in the database table should not end up 
being faster.

So, is there a difference in the indexing of information?

Also, were actions performed multiple times in each case to see if 
variations in system load were having an impact?

Finally, it would be good to test sql_single with a few thousand 
students in it (and a dozen problem sets for each).  The class you are 
timing against can be normal sized, but imagine a large site or one 
which has not removed information from their database for a few 
semesters.  With sql_single, this adds to the size of the database 
tables.  If the tables are not indexed optimally, it may not show itself 
until there is a huge amount of data in the database, but can then 
really slow down.

John


Sam Hathaway wrote:

> Here is some timing data from Mike:
>
>> All of this data was taken on the development machine:  
>> devel.webwork.rochester.edu
>>
>> The quick summary is:
>>
>>
>> Summary:  Taken from data attached. Time is in seconds and is real 
>> time, not CPU time,
>>  so it is only useful for long processes.  "diff = " measures the 
>> time from when the ContentGenerator
>> module is called to the time it returns.
>>
>> Adding  class list of 160 students:
>> [Sat Oct 16 10:19:56 2004] 96404 1097936396 - 
>> [/webwork2/test_gdbm/instructor/users/] [diff = 3.000000 gdbm]
>> [Sat Oct 16 10:36:13 2004] 96406 1097937373 - 
>> [/webwork2/test_sql/instructor/users/] [diff = 6.000000 sql]
>> [Sat Oct 16 10:20:07 2004] 96403 1097936407 - 
>> [/webwork2/test_single_sql/instructor/users/] [diff = 3.000000 
>> sql_single]
>>
>>
>> Assign set 1 (12 problems) to 160 users:
>> [Sat Oct 16 10:50:11 2004] 96403 1097938211 - 
>> [/webwork2/test_gdbm/instructor/sets/1/users/] [diff = 154.000000 gdbm]
>> [Sat Oct 16 10:47:11 2004] 96406 1097938031 - 
>> [/webwork2/test_sql/instructor/sets/1/users/] [diff = 70.000000 sql]
>> [Sat Oct 16 10:51:38 2004] 96404 1097938298 - 
>> [/webwork2/test_single_sql/instructor/sets/1/users/] [diff = 
>> 61.000000 sql_single]
>>
>> Assign 160 users to sets 2, 3, and 4  (41 problems)  (using 
>> Instructor tools page)
>> [Sat Oct 16 10:50:11 2004] 96403 1097938211 - 
>> [/webwork2/test_gdbm/instructor/sets/1/users/] [diff = 154.000000 gdbm]
>> [Sat Oct 16 10:47:11 2004] 96406 1097938031 - 
>> [/webwork2/test_sql/instructor/sets/1/users/] [diff = 70.000000 sql]
>> [Sat Oct 16 10:51:38 2004] 96404 1097938298 - 
>> [/webwork2/test_single_sql/instructor/sets/1/users/] [diff = 
>> 61.000000 sql_single]
>>
>> Assign set 5 (7 problems) to 160 students from the instructor tools 
>> page:
>> [Sat Oct 16 14:57:39 2004] 96406 1097953059 - 
>> [/webwork2/test_gdbm/instructor/assigner/] [diff = 89.000000 gdbm]
>> [Sat Oct 16 14:54:57 2004] 96404 1097952897 - 
>> [/webwork2/test_sql/instructor/assigner/] [diff = 136.000000 sql]
>> [Sat Oct 16 15:17:46 2004] 96406 1097954266 - 
>> [/webwork2/test_single_sql/instructor/assigner/] [diff = 65.000000 
>> sql_single]
>>
>>
>> score sets 0 to 5:
>> [Sat Oct 16 15:44:20 2004] 96406 1097955860 - 
>> [/webwork2/test_gdbm/instructor/scoring/] [diff = 67.000000 gdbm]
>> [Sat Oct 16 15:46:00 2004] 96406 1097955960 - 
>> [/webwork2/test_sql/instructor/scoring/] [diff = 76.000000 sql]
>> [Sat Oct 16 15:41:58 2004] 96403 1097955718 - 
>> [/webwork2/test_single_sql/instructor/scoring/] [diff = 73.000000 
>> sql_single]
>>
>> view library (setDerivatives1, 30 problems displayMode=images)
>> [Sat Oct 16 15:50:43 2004] 96406 1097956243 - 
>> [/webwork2/test_gdbm/instructor/setmaker/] [diff = 13.000000 gdbm]
>> [Sat Oct 16 15:51:45 2004] 8926 1097956305 - 
>> [/webwork2/test_sql/instructor/setmaker/] [diff = 15.000000 sql]
>> [Sat Oct 16 15:52:19 2004] 8926 1097956339 - 
>> [/webwork2/test_single_sql/instructor/setmaker/] [diff = 17.000000 
>> sql_single]
>>
>> ---- This last one is a bit puzzling.  Why is single_sql slower than 
>> sql?
>>
>> The other readings were all pretty short. It's clear that single_sql 
>> speeds up assigning problems.
>> It wonder why it doesn't do even better than that.  Why is the 
>> library display slow in single_sql?
>>
>> In general single_sql is at least as good as the competition so there 
>> are no deal stoppers.
>>
>> Take care,
>> Mike
>>
>>