[Zope] NOTICE: issue with database packing in current Zope releases

[Brian Lloyd]

Hi all,

Jim found a problem with the algorithm for packing the Zope
database that we wanted to announce so that folks can avoid 
being bitten by it until the fix is out (in b4).

The gist of it is that you should not pack your database to 
a given time and then subsequently  pack the database to an 
*earlier* time. For example, do not pack to "older than 0 days"
and then pack to "older than 10 days". The algorithm in the 
current Zope releases doesn't handle this correctly and 
depending on the exact circumstances can end up getting rid 
of objects that it shouldn't in the packed version of the 
database.

Note that if you _are_ inadvertantly bitten by this, you can 
recover by using the Data.fs.old in the /var directory that is 
created at pack time.


Brian Lloyd        brian@digicool.com
Software Engineer  540.371.6909              
Digital Creations  http://www.digicool.com