Alex,

what country do you live in?  I completely sympathize about being the
only one you know.  My friends think I'm insane.

 - michael

On Thu, May 14, 2009 at 10:11 PM, Alex Rufon <[email protected]> wrote:
> The post below is the one thing I miss here as being the "only one" (please 
> notice the quotes) J programmer in my country.
>
> I sort of miss the face to face discussion.
>
> r/Alex
>
> -----Original Message-----
> From: [email protected] 
> [mailto:[email protected]] On Behalf Of Devon McCormick
> Sent: Wednesday, May 13, 2009 8:24 PM
> To: Programming forum
> Subject: Re: [Jprogramming] Strange JDB error.
>
> Oleg -
>
> we spoke about Ken's problem last night at NYCJUG - he's running a 64-bit OS
> (XP) on a machine w/8 GB of RAM.
>
> Your idea about generating tables with the same structure and size is a good
> one, though.
> It sounds like some sort of memory or mapping file corruption is going on.
>
> Regards,
>
> Devon
>
> On Wed, May 13, 2009 at 2:24 AM, Oleg Kobchenko <[email protected]> wrote:
>
>>
>> In order to resolve issues like this, they have to be
>> easily recreated. Could you generate a simple database
>> with fake data but with structure and size similar
>> to yours, so that you can reproduce the issue on that
>> data?
>>
>> It is likely that your machine reaches its limits:
>> being 32-bit and/or amounts of physical memory.
>> This information is also useful.
>>
>>
>>
>> > From: "Lettow, Kenneth" <[email protected]>
>> >
>> > I have been experimenting with JDB for about a month now, and have built
>> > up a database that consists of 7 tables with about 50 million records.
>> >
>> > Recently, after a creating a few versions of the db, I have run into a
>> > problem that I cannot figure out.
>> >
>> > I can initialize the database and import all of the records, and as long
>> > as I don't close the db everything works great.
>> >
>> > Once I close the db and try to reopen it, I am presented with the
>> > following error.
>> >
>> >    db_open DBPATH;DBNAME
>> > |domain error: revert
>> > |   (id)=:len{.    id~
>> >
>> > The strange thing is that the db works perfectly as long as I don't
>> > close it.
>> >
>> > I have tried stepping through the revert verb in JDB and found the line
>> > that fails.
>> >
>> > | [0] if. Tran <: Trans do. return. end.
>> > >>>>|>[1] len=. tranid (1 i.~ <:) Trans   NB. Line that fails with a
>> > domain error.
>> > | [2] map=. 'active';Tcolmap
>> > | [3] ndx=. I. len < #@". &> map
>> > | [4] for_i. ndx do.
>> > | [5]   id=. i{map
>> > | [6]   (id)=: len {. id~
>> > | [7] end.
>> > | [8] deleted=: deleted #~ deleted <: Trans
>> > | [9] Tran=: Trans
>> > | [10] Tdelete=: Tinsert=: ''
>> > | [11] writestate''
>> >
>> > At the point that revert fails the values of Tran, tranid and Trans are
>> > as follows.
>> >
>> >       Trans
>> > 14
>> >       Tran
>> > 25
>> >       tranid
>> > 80$'6929260$8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8
>> > 8 8 8...
>> >
>> > Any suggestions?
>> >
>> > Thanks,
>> >
>> > Ken
>> >
>> > ----------------------------------------------------------------------
>> > For information about J forums see http://www.jsoftware.com/forums.htm
>>
>>
>>
>>
>> ----------------------------------------------------------------------
>> For information about J forums see http://www.jsoftware.com/forums.htm
>>
>
>
>
> --
> Devon McCormick, CFA
> ^me^ at acm.
> org is my
> preferred e-mail
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm
>



-- 
 - michael dykman
 - [email protected]

 - All models are wrong.  Some models are useful.
----------------------------------------------------------------------
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