[ZODB-Dev] Recovering from a POSkeyerror

Tim Peters tim at zope.com
Mon Jan 17 14:46:06 EST 2005


[Paulo Eduardo Neves]
> No need to read this message. I've solved my problem. I'm just posting to
> make it appear in Google. Thanks for the help.

You are a tiger, Paulo!  That's some intense debugging work.  Thank you for
sharing the outcome (and getting it into Google).  I'm glad a current
fsrefs.py gave better clues, anyway.

...
> Versions are bad, bad, bad. Deleted them all. Never more will touch one
> of these.

Versions are widely disliked, although they may work better in a current
ZODB.  It's hard to say.  Jeremy Hylton long ago wrote tests for a lot of
version scenarios that weren't tested at the time, and found a lot of bugs.
I don't know the history of which releases of ZODB got various version
fixes.  My impression, though, is that versions are still "under-tested";
this is educated intuition based on the still-low ratio of number of version
tests to lines of code implementing versions (versions complicate code all
over the place, all the way down to the low-level format of .fs files).

In any case, use of versions is officially discouraged:

    http://mail.zope.org/pipermail/zodb-dev/2004-July/007641.html




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