bdb 4.2->4.3 upgrade

[Branko Čibej]

Max Bowsher wrote:
>>> so I've got a couple of questions: (1) The
>>> README attached below - does it seem accurate and safe?  (2a) Is the
>>> part about deleting log files (taken from faq.html) necessary,
>>>       
>> Yes.
>>     
>
> Question for Branko: Why should deleting unused logfiles be necessary?
> Desirable to save disc space, yes, but they shouldn't impede the
> upgrade... should they?
>   
IIRC that's what the BDB docs say. "Ours not to reason why," especially 
where BDB is concerned. :)

>> This looks like a dangerous thing to do, because one of the still-active
>> processes might want to create a new log file and would fail miserably
>> in the middle of a transaction.
>>     
>
> I would hope that in this circumstance, BDB would simply set the panic
> flag in the environment, causing all processes to stop using it ASAP.
>
> Then, the panic and unfinished transactions would be cleaned up by
> recovery run below.
>
> I can't point to any specific documentation that states the above is
> true, but for a enterprise-class database product to corrupt data due to
> a temporary failure to create a file would be a bit ridiculous.
>   
Certainly. However, since the BDB docs don't explicitly recommend this, 
I'd be reluctant to write upgrade instructions like that.

-- Brane