[ZODB-Dev] Find references to an object

[JohnD.Heintz]

Won't the self-packing and garbage collecting variant of BerkeleyStorage=20
maintain this info?  Trade space for time and all that.

John

On Wednesday 08 August 2001 15:15, Jeremy Hylton wrote:
> >>>>> "GW" =3D=3D Greg Ward <gward@mems-exchange.org> writes:
>
>   GW> ZODB gurus -- given an OID, is it possible to find all objects
>   GW> that reference that object?
>
> I don't believe any storage has a feature like this.  A storage only
> needs to know about the other direction to do GC.
>
>   GW> Perhaps what I'm looking for is this: a sneaky, underhanded way
>   GW> to load object A, find the list of all objects (OIDs) it
>   GW> references, and see if object B is in that list.  If so, add
>   GW> object A to the list of objects referencing B.  Repeat
>   GW> database.objectCount() times.  The problem I see with this is
>   GW> how to deal with extension types like BTree, which reference
>   GW> lots of objects in an opaque way.
>
>   GW> Any suggestions?
>
> If you have objects A and B, it should be possible to get a list of
> everything referenced by A and see if B is in that list.
>
> Jeremy
>
>
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--=20
=2E . . . . . . . . . . . . . . . . . . . . . . .

John D. Heintz | Senior Engineer

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