SegmentMap is corrupted

[Ruslan Zasukhin]

On 13/2/07 10:52 PM, "Steve Albin" <steve at steve-albin.com> wrote:

>>> Is the segmentmap corruption something that can happen due to a bug in my
>>> app?
>>> What kind of thing could cause this?
>> 
>> This error can be expected in case of many new WRITE into db without Flush,
>> Then interrupt application (crash, system failure).
> 
> This is interesting.  This database had very few writes done to it except for
> the Convert_1_2.  My old app used Valentina 1 and this user has been using it
> for years with no problem.  I am trying to upgrade my app to use Valentina 2,
> but so far without success for this user.  (You can see my Mantis reports
> under id steveja7.)   At this point, he is beta testing the app.  Data entry
> for this app is primarily record by record from user data entry.  The only
> high volume writing to the DB would be the convert.  Also, he has not reported
> any hard crashes except for the one resulting from the segmentmap corruption.
> 
> Also, this user has, by far, the largest database of any of my users. So there
> are many more writes done on the conversion than for my other users, all of
> whom have not reported this problem.  (I only have about a half dozen users
> for this version - not many I admit.)

I do not think it is related to Convert_1_2().
You can convert_1_2 then flush or db.close()
Done.

It is out of game.

> We have had a segmentmap corruption previously that was isolated to adding a
> new VText field to a database converted from Val 1 to Val 2.  That has been
> fixed.  Now I'm wondering if there is some other error resulting from the
> conversion process.

>> clone
> 
> Did not work for me, but I am going to try it again.  Maybe there was
> something wrong with the way I did it as it took 4 hours.

Clone cannot produce db with already bad segment map..
If it do -- this is bug. So far nobody else meet this.

So assume cloned db is fine.
Then some NEXT operation cause corruption.

> I have repeated the steps my user has done, but it won't crash for me.   But,
> I know it is crashing for him because he is sending me the V4RB_Logs that I
> have turned on for his app.  I think it may be some internal timing issue that
> I can't reproduce.  He is on a fast Windows machine and I am using Virtual PC.
> My Mantis report has the small project that he has used to reproduce the error
> with his database.
> 
> It is also difficult to work on this problem with my user being hundreds of
> miles away.  I have to rely on him telling me accurately what he is doing.
> Not always an easy task.  But, with this information about segmentmap errors,
> I will try to step back and recreate everything with this in more focus.

We have PCs so we can try your app + db + steps later.

-- 
Best regards,

Ruslan Zasukhin
VP Engineering and New Technology
Paradigma Software, Inc

Valentina - Joining Worlds of Information
http://www.paradigmasoft.com

[I feel the need: the need for speed]