[ZODB-Dev] Re: [Zope-Checkins] CVS: ZODB3/ZODB - FileStorage.py:1.105.2.6.2.2

Barry A. Warsaw barry@zope.com
Mon, 18 Nov 2002 09:55:55 -0500


>>>>> "TD" == Toby Dickenson <tdickenson@geminidataloggers.com> writes:

    >> Two important fixes for backpointer handling.

    TD> Backpointers seem to attract more than their fair share of
    TD> bugs.

    TD> Their only use is to avoid copying bulk data during an undo,
    TD> right? Do we know how much space is actually being saved? I
    TD> wonder if they are worth the extra complexity in FileStorage.

    TD> (not that there is anything we can do to change this now....)

BTW, backpointers exist in Berkeley storage too, but here they're a
pointer which is combined with the oid to point into a table of
pickles.  Really they're just the tid of the transaction that wrote
the data.  So there's very little additional complexity for those
storages.

-Barry