On 2016-10-04 15:58, Thomas Mueller wrote:
Hi,
I still do not understand, why we do not delegate the UUID
generation/lookup to the persistence instead of insisting it to be just
like any other property index...
The UUID _generation_ is not a problem. (I it a bit slow, but scales well
- no issue there). The UUID _lookup_ is not a problem either. The problem
is indexing, because this is a unique index (wasted storage space, wasted
CPU and latency). The issue is, in most cases there is no need for this
UUID. So why index it. Sure, we could improve indexing (improve unique
property indexes). But it would be easier to not index those nodes at all.
...
At least in our DocumentStoreImplementations (Mongo and RDB), making the
UUID something indexed by the storage (so either Mongo or the relational
database) should be relatively cheap (after all, the UUID never changes
once assigned, right?). That would eliminate the indexing overhead in
Oak itself completely.
Best regards, Julian
