Sanity check

[Brian K. White]

sync is just about 100% of the time irrelevant. Any time you think you 
need a sync, your really needed something else, like close() or printer 
flush or printer reset etc. I say only irrelevant not wring, because it 
should also never hurt, except hurting performance, so merely irrelevant.

I think one big source of dknf is modifying any of the index fields in 
an index during a lookup by that index. Especially in browse processing.
-- 
bkw


On 6/2/20 3:58 PM, William J. McEachran via Filepro-list wrote:
> On Tue, 2 Jun 2020 at 12:10, Fairlight via Filepro-list <
> filepro-list at lists.celestial.com> wrote:
>
>> It's the result of bad BTree+ code.
>>
>> If you go through this demo, you'll see when data needs to be split.
>> Something about it is incorrectly handled in fP, resulting in bad
>> indexes.
>>
>> https://www.cs.usfca.edu/~galles/visualization/BPlusTree.html
>>
>>
> I got lucky and found that the nightly tar archive  had the troubled data.
> I was able to play around with it on a test system and found I could get a
> DKNF (deleted key not found) error on the data in addition to the sanity
> check
> The data is part of a simple routine that is created and used in a single
> process ... so it easily traceable.
>
> All lookups involved in record operations (creating, deleting, modifying)
> are protected (-p flag) lookups.
> Each record operations concludes with a write - 'write [lookupname''.
>   Create a record; write that record.  Delete a record; write that record.
> etc.
> The routine concludes with a 'sync'.
>
> So I can't think of anything that I've missed to cause invalid key/index
> issues.
> Did I miss something?
> -------------- next part --------------
> An HTML attachment was scrubbed...
> URL: <http://mailman.celestial.com/pipermail/filepro-list/attachments/20200602/7d8f4995/attachment.html>
> _______________________________________________
> Filepro-list mailing list
> Filepro-list at lists.celestial.com
> Subscribe/Unsubscribe/Subscription Changes
> http://mailman.celestial.com/mailman/listinfo/filepro-list