UsingWW: Alberto Candel - dataMunger.pl

$inactiveTopic$ dataMunger.pl

topic started 11/22/2004; 10:23:32 PM
last post 11/24/2004; 9:55:31 PM

$user$ Alberto Candel - dataMunger.pl $blueArrow$
11/22/2004; 10:23:32 PM (reads: 1005, responses: 6)

One of our instructors was trying to extend the due date for a set but it failed for one student. I tried and the same.

When clicking [Modify Problem set for Student] (for that one student and that one set), I get the following:

Error in dataMunger.pl:
     Can't find record with psvn=
                                    in the database

I guess this student's psvn record got lost, and I am unable to find it. I think that he had one at some point, as there is one in the file /logs/xxx_bak1.psvnlog. When I try to use that number in the utitlity [Examine or change data for PSVN], dataMunger.pl reports it can't find the record in the database.

Any suggestions as to how to fix this?

Thanks,

Alberto

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$user$ Alberto Candel - Re: dataMunger.pl $blueArrow$
11/22/2004; 10:42:11 PM (reads: 1172, responses: 0)

As soon as I wrote the previous post, I figured out how to fix the problem! I only needed to build the set again.

What I don't know is this. If there was a PSVN for this student in the backup file, maybe he actually had a set at some point. Is there a way to find that out and recover his work?

Alberto

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$user$ Arnold K. Pizer - Re: dataMunger.pl $blueArrow$
11/23/2004; 4:05:36 PM (reads: 1165, responses: 0)

The most logical explanation (and the only one I know)is that the student's set was deleted. A "professor" would have had to do this. When this is attempted, there is a warning message that the lost data is unrecoverable. When a set is deleted, all records of what the student did are also deleted with 2 exceptions:(1) if the set was scored, the scoring data is not deleted and (2) any activity logged in the access log remains.

The /logs/xxx_bak1.psvnlog file you refer to can be used to recreate the assignment. In particular it saves problem seeds so that the constants used in student problems can be recovered. This is usually only used if the database gets corrupted (or if someone with professor permission "accidently" deleted sets). I know of only two cases in the past when this was necessary.

If you have the access log turned on, you can search for activity from the student. But the access log is huge and it is probably not worth the effort.

Arnie

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$user$ Alberto Candel - Re: dataMunger.pl $blueArrow$
11/24/2004; 2:51:09 AM (reads: 1150, responses: 0)

Thanks Arnie. I didn't know what those numbers after the PSVN were for. So I was able to recreate the same assignment.

Now it happens that this student had done work on the set that "disappeared" because by clicking on [Show Past Answers] I can see his old answers there. But these old answers don't show up in the usual way when starting the assignment (checking Show My Old Answers before getting a problem shows blanks).

So the student will be able to enter his old answers. Out of curiosity I looked into the answer.log file and located his entries. There is a number there that I was not able to figure out:

|name|HW3|1|  1098240749          A   B    C

What is the long number for?

Thanks,

Alberto

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$user$ Arnold K. Pizer - Re: dataMunger.pl $blueArrow$
11/24/2004; 9:47:49 AM (reads: 1154, responses: 1)

Hi Alberto,

I had forgotten about the answer_log. That is a much better place to look for answers than the access log.

The number (e.g. 1098240749) that you can't figure out:

|name|HW3|1| 1098240749 A B C

is the date/time. It's in the form Perl uses (i.e. the number of ellapsed seconds since 1/1/1980). We probably should make this human readable in WeBWorK 2. If you need to translate it, do a Google search for "perl localtime".

Arnie

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$user$ Davide P. Cervone - Re: dataMunger.pl $blueArrow$
11/24/2004; 2:05:21 PM (reads: 1311, responses: 0)

There is a human readable timestamp in WW2, but this internal format time is used by the ShowAnswers script for sorting and for deciding what constitutes a 'session' (i.e., when to insert a horizontal line indicating that the student went away to think about it). Casual changes to this value will cause ShowAnswers to work improperly. This happened in the conversion to WW2, and I have straightened it out, but this value in particular is used in subtle ways.

Davide

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$user$ Alberto Candel - Re: dataMunger.pl $blueArrow$
11/24/2004; 9:55:31 PM (reads: 1126, responses: 0)

I guess I was just curious about how this student's assignment disappeared. The instructor told me that it happened when she was changing the date for a single student, so now it makes sense that only this student record got lost. I don't know how this could happen because the delete button is far from the set time button and because she was able to do it for other sets. But who knows, we are all newbies to WW here.

Anyway, with your indications I was able to recreate the same set. The students old answers are there, they just don't pop up as usual. So I thought that the Perl Age number was the key to make them pop up. But it looks difficult (to me), and since the student can do it, it is not worth the time trying to do it myself.

Thanks for your help, and Happy Thanksgiving.

Alberto

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