Re: btree on disk

Hello Natalia;

If I were to put records inside a BTreeFiler in a way:


filer.writeRecord(new Key(somekeyvalue),new Value(somevalue))

and then search this filer based on somekeyvalue, would I have to use a
ValueIndexer?

A typical operation is for adding nodes to a graph is:

record r;
if(filer.readRecord(new Key(keysearched))==null)
{
   r = new Record(new Key(keysearched), new Value(somevalue));
   filer.writeRecord(r);
}
else
{
  r = filer.readRecord(new Key(keysearched));
}

it otherwords, I have to check if a graph contains a node n, if it does not
write a new node, and if it does retrieve the node. I need to be able to do
this very fast. I have tried object oriented dbms, although they worked
nicely for graph things, they were very poor at identity search.

Any ideas, recomendations and help greatly appreciated,
-C.B.

On 7/9/07, Natalia Shilenkova <[email protected]> wrote:
>
> On 7/9/07, Cam Bazz <[email protected]> wrote:
> > Hello All,
> >
> > That was really helpful. Thanks.
> >
> > I also noticed FSFiler, and HashFiler. Are those for Indexing files?
>
> Xindice allows several way for the data to be stored. Currently it has
> BTreeFiler (based on tree-like structure), HashFiler (based on hash
> table), FSFiler (uses file system), MemFiler (in-memory), and
> SizableMemFiler (in-memory). A document collection can be configured
> to use any of those filers, depending on collection characteristics.
>
> Additionally, collection can have an index. There are 3 indexers in
> Xindice now: NameIndexer, ValueIndexer, and MemValueIndexer.
>
> > I am working on a graph database project. I have tried several oodbms,
> and
> > finally decided to build my own.
> >
> > Also, could it be possible to use xindice as a backend for Jena?
>
> No idea, really. Never heard of Jena before.
>
> Regards,
> Natalia
>