Hi,

Can anybody explain to me how does Jena map node to nodeId? The following is 
stated in http://jena.apache.org/documentation/tdb/architecture.html


"The Node to NodeId mapping is based on hash of the Node (a 128 bit MD5 hash - 
the length was found not to major performance factor).

The default storage of the node table is a sequential access file for the 
NodeId to Node mapping and a B+Tree for the Node to NodeId mapping."

My understanding is that Jena hashes the node into a long integer, and somehow 
converts the hashed value into an address offset to the node table, and the 
node information is stored at the address offset in the node table.

Is my understanding correct? How does Jena converts the hashed value into an 
address offset? How is B+ tree used in this process?

Thanks!
Yi Liao

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