[elephant-devel] postmodern btree problem

Hugo Duncan hugo_duncan at yahoo.com
Fri Jan 2 18:52:34 UTC 2009


On Fri, 02 Jan 2009, Alex Mizrahi wrote:
>  HD> I am having trouble reducing the code to a sensible test case that
>  HD> exhibits the same behaviour.  Any suggestions on how I can track  
> this
>  HD> down?

> what kind of objects do you put in this btree? i think i've seen a  
> problem with upgrading btree object type, it might be related.

I am storing objects of a single persistant class, with 7 slots containing  
integers or floats, into the btree.  The keys are integers.  Changing the  
class to be a standard class does not cange the problem.

>  what's the structure of your code? do you just get slot's value and  
> read/write
>  to btree, or something else?

The btree is created on object creation, and only has key/values inserted  
and read.

>  do you have transactions that are aborted?

No, I have a single transaction (WITH-TRANSACTION) around my test case,  
and I start with an empty (freshly created) database.  I notice however,  
that a EXECUTE-TRANSACTION is being run for each persistant object I  
create within the WITH-TRANSACTION body.  ELEPHANT:*CURRENT-TRANSACTION*  
doesn't seem to be bound, so the ENSURE-TRANSACTION wrapping the object  
creation is calling EXECUTE-TRANSACTION.  Attached is a small test case  
and its output when I run it.

I'm not sure that is causing my problems though, as other code exhibits  
the same behaviour and runs OK.

>  do you have multiple threads?

No, single thread.

Thank you, Alex, for taking the time to help with this.

Hugo
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