On 18.12.12 15:30, Stefan Guggisberg wrote:
On Tue, Dec 18, 2012 at 4:08 PM, Michael Dürig <[email protected]> wrote:
On 18.12.12 14:43, Thomas Mueller wrote:
Hi,
2) Allow inconsistent journals.
I guess we don't want that. But the question is how close the journal
has
to match the original commit, specially "move" and "copy" operations. If
they need to be preserved (do they?), then it's complicated.
There is no use for a journal which is not accurate. After all, if we
consider implementing rebase (OAK-464) on top of the journal, it has to
be accurate.
Yes, I think we should have a consistent journal, if we have a journal.
But the question is how close the journal has to match the original
commit, specially "move" and "copy" operations.
So, do "move" and "copy" operations need to be preserved, or can they be
converted to "add node" / "remove node"?
Now we are getting somewhere: This is exactly the original topic of OAK-464.
If the Microkernel converts moves to add/remove, implementing rebase on top
of that results in moves of big sub trees to become *very* expensive.
IIRC we didn't consider efficient move operations a design goal.
i guess we can live with non-optimized move operations.
Right. However, degrading moves to remove/add node operations limits the
size of sub trees which can be moved: if the moved sub tree (serialised
to json add node operations) do not fit into heap, moves wont work at all.
Michael
cheers
stefan
Michael
Regards,
Thomas
