[ZODB-Dev] BTrees and id mapping (was Re: Data.fs size grows non-stop)

Pedro Ferreira jose.pedro.ferreira at cern.ch
Mon Dec 14 05:17:10 EST 2009

David Glick wrote:
> Pedro Ferreira wrote:
>> Hello all,
>> So, I've been experimenting with a new structure for our date indexes, 
>> and I was considering using an IOBTree that would map integer timestamps 
>> to BTree-based sets. As for the sets, I considered two options:
> Be careful with using timestamps as IOBTree keys.  By default this type 
> of BTree uses the system integer, which on many systems is 32 bits.  
> That means that you'll overflow the maximum allowed key for timestamps 
> beyond the year 2038.  It won't even give an error; it will just 
> silently overflow and overwrite existing values in the BTree.
Yes, I know. That's one of the reasons I'm using YYYYmmdd integers 
instead (the other one being i only need 1 day resolution).

Thanks a lot for the tip!


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