Hi, <shameless plug explanation="my blog"> You can find a decent explanation for pre-1.4 storage layout here:
http://digitalstain.blogspot.com/2010/10/neo4j-internals-file-storage.html It has not been updated however to explain extended addressing for 4B+ entities in a db (which do not change the layout, just the semantics of some bits). Nevertheless, the basic structures (fixed size records, doubly linked list etc) are still there. For the way I/O is performed (and minimized/improved upon) you can look at the way memory mapping is used here: http://digitalstain.blogspot.com/2010/10/neo4j-internals-persistence-and-memory.html And of course, there is object caching explained here: http://digitalstain.blogspot.com/2010/10/neo4j-internals-caching.html </ shameless plug> The organization in general is greatly favored by SSDs which are more friendly to linked lists on disk. However, there is no optimization in place yet targeting a specific storage technology - as in most applications, the better the I/O performance, the better Neo4j does. I'd be happy to help dive into more specific questions as they come to you. cheers, CG On Wed, Sep 14, 2011 at 8:09 PM, danielb <[email protected]> wrote: > Hello everybody, > > I have some questions regarding data storage in neo4j. How does neo4j store > the data on the physical level? Are elements which have a close relationship > in the graph stored in an adjacent way on disk? Any special binary format? > How do you treat SSDs compared to common harddisks? What are your measures > to improve I/O? Is there a technical documention which describes this? > > regards, > Daniel > > -- > View this message in context: > http://neo4j-community-discussions.438527.n3.nabble.com/Neo4j-low-level-data-storage-tp3336483p3336483.html > Sent from the Neo4j Community Discussions mailing list archive at Nabble.com. > _______________________________________________ > Neo4j mailing list > [email protected] > https://lists.neo4j.org/mailman/listinfo/user > _______________________________________________ Neo4j mailing list [email protected] https://lists.neo4j.org/mailman/listinfo/user
