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

[Toby Dickenson]

On Monday 18 November 2002 2:55 pm, Barry A. Warsaw wrote:
> >>>>> "TD" =3D=3D Toby Dickenson <tdickenson@geminidataloggers.com> wri=
tes:
>     >> 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.

I *think* it would allow you to eliminate the pickleRefcounts table?

Managing the pickleRefcounts doesnt involve many lines of code, but there=
=20
would be a high cost associated with something going wrong there.=20