[elephant-devel] Best way of getting a collection size

[Ian Eslick]

 > This probably isn't possible for the BDB data store.  You can get  
the leaf count for a BDB
 > Btree, but not for a subtree (we multiplex Elephant BTrees on a  
single, large BDB BTree).

It's not that BDB doesn't provide a count, it's that the way we use  
their DB doesn't make that count useful.  We don't have a 1:1 mapping  
between lisp persistent-collections and BDB btrees, instead we have  
an N:1 lisp btree->BDB btree.  I don't have time to go into all the  
good reasons why, but the problem is on our end of things.

Ian

On Oct 2, 2007, at 12:46 PM, Mariano Montone wrote:

> Perhaps we could provide a mixin class that automatically maintains
> this count on the lisp side for a user subclass of persistent-
> collection?
>
> Ok. I may try that. It's astonishing for me that the BDB api does  
> not provide such functionality.
>
> Thanks, Mariano
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