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From Tim Dudgeon <tdudg...@informaticsmatters.com>
Subject Re: db.lck and dbex.lck files
Date Sat, 30 Sep 2006 08:41:19 GMT
Stanley Bradbury wrote:
> Tim Dudgeon wrote:
>>
>>
>> I'm wanting to provide some feedback in my application when a derby 
>> database is opened and it was not shutdown properly last time it was 
>> used.
>>
>> 2 files seem to be created, db.lck and dbex.lck and are not deleted 
>> when the db is not shutdown cleanly.
>>
>> Is there a way of distinguishing between the presence of these files 
>> being the result of a current process holding a lock on an open 
>> database (in which case the database cannot be opened) and it being 
>> the result of a bad shutdown, in which case the database can be 
>> opened, but there may be a delay whilst it is opened.
>>
>> thanks
>>
>> Tim
>>
>>
> Hi Tim -
> As you indicate, check if the files are locked by a process - if they 
> are then the database is most likely in use by a Derby process.  If they 
> are not locked 

So how best to do this? Is File.canWrite() sufficient?

then they are probably orphan files and then you can
> check for the number and size of the files in the 'log' subdirectory 

Any files in particular? There always seems to be files in here.

> to 
> see if there might be a delay due to recovery running when the DB is 
> next booted.  And I know you wouldn't do this but I feel compelled to 
> mention that  you should never directly manipulate these files in any way.

Of course :-)

Thanks

Tim


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