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

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On Oct 21, 2004, at 2:04 PM, John Jones wrote:

> 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.

The way sql_single is implemented currently is to have separate tables 
for each course in a single database. (Tables are named like 
"$courseID\_$sqlTableName".) There isn't a difference in table size.

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

I think that the "sql" courses did not have indexing enabled. If I'm 
right, the "sql versus sql_single" data would mostly reflect 
"non-indexed versus indexed" differences.

> 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
>>>
>>>
>
>
>
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